[FW][REF] plugin cell: use a new command "CLEAR_CELLS"

[fw-bot]

for performance and clarification reasons, groups
the dispatch commands "CLEAR_CELL" with a single
command "CLEAR_CELLS" where possible.

Task : 4095732

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

Forward-Port-Of: #4782

[robodoo]

[fw-bot]

@laa-odoo @LucasLefevre cherrypicking of pull request #4782 failed.

stdout:

CONFLICT (modify/delete): src/helpers/clipboard/clipboard_cells_state.ts deleted in bee93a46dc3e1c1bbbb87336a6aca5117448228c and modified in a454b43527d8579d0f2a1d29dee886b03335bd1d.  Version a454b43527d8579d0f2a1d29dee886b03335bd1d of src/helpers/clipboard/clipboard_cells_state.ts left in tree.
Auto-merging src/plugins/core/cell.ts
CONFLICT (content): Merge conflict in src/plugins/core/cell.ts
Auto-merging src/plugins/core/merge.ts
Auto-merging src/plugins/core/sheet.ts
Auto-merging src/plugins/ui_feature/data_cleanup.ts
Auto-merging src/plugins/ui_stateful/clipboard.ts
CONFLICT (content): Merge conflict in src/plugins/ui_stateful/clipboard.ts
Auto-merging src/registries/repeat_commands_registry.ts
Auto-merging src/types/commands.ts
Auto-merging tests/repeat_commands_plugin.test.ts
Auto-merging tests/test_helpers/commands_helpers.ts
Auto-merging tests/test_helpers/constants.ts
CONFLICT (content): Merge conflict in tests/test_helpers/constants.ts

Either perform the forward-port manually (and push to this branch, proceeding as usual) or close this PR (maybe?).

In the former case, you may want to edit this PR message as well.

⚠️ after resolving this conflict, you will need to merge it via @robodoo.

More info at https://github.com/odoo/odoo/wiki/Mergebot#forward-port

[rrahir]

@robodoo r+