task(vmop): add migration progress status and reasons

[danilrwx]

Description

Implement VMOP migration progress reporting and make sync-phase progress more informative and stable.

Changes in this PR:

• add status.progress support for migration VirtualMachineOperation objects;
• add detailed Completed reasons for migration lifecycle stages;
• centralize sync progress range in migrationprogress.SyncRangeMin/SyncRangeMax;
• add a dedicated migration progress package with mapper/strategy logic;
• consume KubeVirt migration transfer details from status.migrationState.transferStatus when they are available;
• keep degraded time/phase-based progress as a fallback when transfer details are unavailable;
• reduce repeated artificial stall bumps in degraded mode.

Why do we need it, and what problem does it solve?

Migration VMOP progress was previously coarse and bursty. In practice users could observe sequences like 1 -> 2 -> 3 -> 16 -> 41 -> 42..51 -> 100, where the visible progress was driven by reconcile cadence and fallback estimation rather than by the actual migration state.

This PR improves the user-facing progress model by:

• exposing progress directly in VMOP status;
• providing stage-specific reasons such as disks preparation, target scheduling, target preparation, syncing, source suspended, and target resumed;
• improving sync-phase progress calculation so it can consume KubeVirt migration transfer counters and runtime signals from transferStatus when they are available;
• keeping the old degraded estimator as a compatibility fallback;
• preventing the previous near +1 per reconcile behavior from the stall bump logic.

As a result, migration progress becomes more actionable for users and easier to debug from VMOP conditions.

This PR depends on the matching 3p-kubevirt API change that moves migration transfer-related fields under VirtualMachineInstanceMigrationState.transferStatus.

What is the expected result?

1. Start a VM migration through VirtualMachineOperation.
2. Observe status.progress on the VMOP object.
3. During early lifecycle phases, progress should move through the coarse stage milestones.
4. During sync, progress should stay within the configured sync range and advance more naturally.
5. When KubeVirt exposes status.migrationState.transferStatus, sync progress should use those runtime values.
6. Completed condition reasons should reflect the current migration stage.
7. In environments where migration transfer details are not available yet, degraded fallback should still work without repeated artificial increments on every reconcile.

Checklist

• The code is covered by unit tests.
• e2e tests passed.
• Documentation updated according to the changes.
• Changes were tested in the Kubernetes cluster manually.

Changelog entries

section: core
type: feature
summary: "Add VMOP migration progress reporting with detailed lifecycle reasons and smoother sync-phase progress calculation."
impact_level: low