[IMP] pivot: single format for measure

[hokolomopo]

Currently, in spreadhseet pivot the format is the format of the first cell matching the domain of the pivot cell. That means that different pivot cells on the same measure can have different formats.

Now the format is determined by the measure itself, so all cells with the same measure will have the same format. The commit also adds getMeasureFormat to the pivot's interface to get this format.

Description:

description of this task, what is implemented and why it is implemented that way.

Task: : TASK_ID

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