feat: don't switch zone for dns command (#750)

# Description

The DNS command are not zone dependent, so this MR remove the need to
change the zone for DNS command.

The reason behind that: I created a role for DNS challenge for getting
web certificate.
```
{
  "default-service-strategy": "deny",
  "services": {
    "dns": {
      "type": "rules",
      "rules": [
        {
          "expression": "parameters.has('type') && parameters.type != 'TXT'",
          "action": "deny"
        },
        {
          "expression": "parameters.has('name') && !parameters.name.startsWith('_acme-challenge')",
          "action": "deny"
        },
        {
          "expression": "resources.has('dns_domain_record') && resources.dns_domain_record.has('type') && resources.dns_domain_record.type != 'TXT'",
          "action": "deny"
        },
        {
          "expression": "resources.has('dns_domain_record') && resources.dns_domain_record.has('name') && !resources.dns_domain_record.name.startsWith('_acme-challenge')",
          "action": "deny"
        },
        {
          "expression": "operation in ['list-dns-domains', 'list-dns-domain-records', 'get-dns-domain-record', 'create-dns-domain-record', 'delete-dns-domain-record']",
          "action": "allow"
        }
      ]
    }
  }
}
```

I wanted to test if my role allows only the TXT records that I wanted.
The easiest was to test with the exo cli.

However, due to the `SwitchClientZoneV3`, the role need also the
permission `compute.list-zones` (or something similar), if I want to
edit DNS Records with the exo cli, which is not needed for the tools
like lego or cert-manager.

From what I understood, the client will be created within the
`buildClient`. Let me know if I missed something.

## Checklist
(For exoscale contributors)

* [ ] Changelog updated (under *Unreleased* block)
* [ ] Testing

## Testing

Create, delete, update DNS records work.

Author: mlec1

cmd/dns/dns_add.go

@@ -7,7 +7,6 @@ import (
 	"github.com/spf13/cobra"
 
 	exocmd "github.com/exoscale/cli/cmd"
-	"github.com/exoscale/cli/pkg/account"
 	"github.com/exoscale/cli/pkg/globalstate"
 	"github.com/exoscale/cli/utils"
 	v3 "github.com/exoscale/egoscale/v3"
@@ -25,10 +24,7 @@ func init() {
 func addDomainRecord(domainIdent, name, rType, content string, ttl int64, priority *int64) error {
 
 	ctx := exocmd.GContext
-	client, err := exocmd.SwitchClientZoneV3(ctx, globalstate.EgoscaleV3Client, v3.ZoneName(account.CurrentAccount.DefaultZone))
-	if err != nil {
-		return err
-	}
+	client := globalstate.EgoscaleV3Client
 
 	domainsList, err := client.ListDNSDomains(ctx)
 	if err != nil {

cmd/dns/dns_create.go

@@ -6,7 +6,6 @@ import (
 	"github.com/spf13/cobra"
 
 	exocmd "github.com/exoscale/cli/cmd"
-	"github.com/exoscale/cli/pkg/account"
 	"github.com/exoscale/cli/pkg/globalstate"
 	"github.com/exoscale/cli/utils"
 	v3 "github.com/exoscale/egoscale/v3"
@@ -31,10 +30,8 @@ func createDomain(domainName string) error {
 	var err error
 
 	ctx := exocmd.GContext
-	client, err := exocmd.SwitchClientZoneV3(ctx, globalstate.EgoscaleV3Client, v3.ZoneName(account.CurrentAccount.DefaultZone))
-	if err != nil {
-		return err
-	}
+	client := globalstate.EgoscaleV3Client
+
 	utils.DecorateAsyncOperation(fmt.Sprintf("Creating DNS domain %q...", domainName), func() {
 		_, err = client.CreateDNSDomain(ctx, v3.CreateDNSDomainRequest{
 			UnicodeName: domainName,

cmd/dns/dns_delete.go

@@ -9,7 +9,6 @@ import (
 	exocmd "github.com/exoscale/cli/cmd"
 	"github.com/exoscale/cli/utils"
 
-	"github.com/exoscale/cli/pkg/account"
 	"github.com/exoscale/cli/pkg/globalstate"
 	v3 "github.com/exoscale/egoscale/v3"
 )
@@ -38,10 +37,7 @@ func init() {
 
 func deleteDomain(ident string, force bool) error {
 	ctx := exocmd.GContext
-	client, err := exocmd.SwitchClientZoneV3(ctx, globalstate.EgoscaleV3Client, v3.ZoneName(account.CurrentAccount.DefaultZone))
-	if err != nil {
-		return err
-	}
+	client := globalstate.EgoscaleV3Client
 
 	domainsList, err := client.ListDNSDomains(ctx)
 	if err != nil {

cmd/dns/dns_list.go

@@ -7,14 +7,12 @@ import (
 
 	"github.com/spf13/cobra"
 
-	"github.com/exoscale/cli/pkg/account"
 	"github.com/exoscale/cli/utils"
 
 	exocmd "github.com/exoscale/cli/cmd"
 	"github.com/exoscale/cli/pkg/globalstate"
 	"github.com/exoscale/cli/pkg/output"
 	"github.com/exoscale/cli/table"
-	v3 "github.com/exoscale/egoscale/v3"
 )
 
 type dnsListItemOutput struct {
@@ -60,10 +58,7 @@ Supported output template annotations: %s`,
 
 func listDomains(filters []string) (output.Outputter, error) {
 	ctx := exocmd.GContext
-	client, err := exocmd.SwitchClientZoneV3(ctx, globalstate.EgoscaleV3Client, v3.ZoneName(account.CurrentAccount.DefaultZone))
-	if err != nil {
-		return nil, err
-	}
+	client := globalstate.EgoscaleV3Client
 
 	domainsList, err := client.ListDNSDomains(ctx)
 	if err != nil {

cmd/dns/dns_records_update.go

@@ -6,7 +6,6 @@ import (
 	"github.com/spf13/cobra"
 
 	exocmd "github.com/exoscale/cli/cmd"
-	"github.com/exoscale/cli/pkg/account"
 	"github.com/exoscale/cli/pkg/globalstate"
 	"github.com/exoscale/cli/utils"
 	v3 "github.com/exoscale/egoscale/v3"
@@ -93,10 +92,7 @@ func updateDomainRecord(
 	ttl, priority *int64,
 ) error {
 	ctx := exocmd.GContext
-	client, err := exocmd.SwitchClientZoneV3(ctx, globalstate.EgoscaleV3Client, v3.ZoneName(account.CurrentAccount.DefaultZone))
-	if err != nil {
-		return err
-	}
+	client := globalstate.EgoscaleV3Client
 
 	domainsList, err := client.ListDNSDomains(ctx)
 	if err != nil {

cmd/dns/dns_remove.go

@@ -8,7 +8,6 @@ import (
 	exocmd "github.com/exoscale/cli/cmd"
 	"github.com/exoscale/cli/utils"
 
-	"github.com/exoscale/cli/pkg/account"
 	"github.com/exoscale/cli/pkg/globalstate"
 	v3 "github.com/exoscale/egoscale/v3"
 )
@@ -37,10 +36,7 @@ func init() {
 
 func removeDomainRecord(domainIdent, recordIdent string, force bool) error {
 	ctx := exocmd.GContext
-	client, err := exocmd.SwitchClientZoneV3(ctx, globalstate.EgoscaleV3Client, v3.ZoneName(account.CurrentAccount.DefaultZone))
-	if err != nil {
-		return err
-	}
+	client := globalstate.EgoscaleV3Client
 
 	domainsList, err := client.ListDNSDomains(ctx)
 	if err != nil {

cmd/dns/dns_show.go

@@ -8,11 +8,9 @@ import (
 	"github.com/spf13/cobra"
 
 	exocmd "github.com/exoscale/cli/cmd"
-	"github.com/exoscale/cli/pkg/account"
 	"github.com/exoscale/cli/pkg/globalstate"
 	"github.com/exoscale/cli/pkg/output"
 	"github.com/exoscale/cli/utils"
-	v3 "github.com/exoscale/egoscale/v3"
 )
 
 type dnsShowItemOutput struct {
@@ -68,10 +66,7 @@ func showDNS(ident, name string, types []string) (output.Outputter, error) {
 	}
 
 	ctx := exocmd.GContext
-	client, err := exocmd.SwitchClientZoneV3(ctx, globalstate.EgoscaleV3Client, v3.ZoneName(account.CurrentAccount.DefaultZone))
-	if err != nil {
-		return nil, err
-	}
+	client := globalstate.EgoscaleV3Client
 
 	domainsList, err := client.ListDNSDomains(ctx)
 	if err != nil {