[IMP] charts: allow to create calendar chart with only dates

[anhe-odoo]

Task Description

Just as we do with the pie chart when we only have one column of strings, we should be able to create a calendar chart with only a column of dates by counting the appearance by granularity. This PR aims to add this possibility, needed for the task 6209080

Related Task

• Task: 6352279

review checklist

• feature is organized in plugin, or UI components
• support of duplicate sheet (deep copy)
• in model/core: ranges are Range object, and can be adapted (adaptRanges)
• in model/UI: ranges are strings (to show the user)
• undo-able commands (uses this.history.update)
• multiuser-able commands (has inverse commands and transformations where needed)
• new/updated/removed commands are documented
• exportable in excel
• translations (_t("qmsdf %s", abc))
• unit tested
• clean commented code
• track breaking changes
• doc is rebuild (npm run doc)
• status is correct in Odoo

[robodoo]