[FIX] composer: change mode to editing when composer cursor selection changes

[fw-bot]

Description:

Current behavior before PR:

• When typing =sum( and pressing the Home key, selecting a range caused weird
  behavior in the composer.
• The same issue occurred when using Ctrl+A to select the entire text.

Desired behavior after PR is merged:

• Changing the cursor selection now correctly switches the mode to 'editing'.

Task: 5226615

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: #7483
Forward-Port-Of: #7400

[robodoo]

[fw-bot]

@rmbh-odoo @VincentSchippefilt cherrypicking of pull request #7400 failed.

stdout:

Auto-merging src/components/composer/composer/abstract_composer_store.ts
Auto-merging src/components/composer/composer/composer.ts
CONFLICT (content): Merge conflict in src/components/composer/composer/composer.ts
Auto-merging src/helpers/pivot/pivot_composer_helpers.ts
Auto-merging tests/composer/autocomplete_dropdown_component.test.ts
Auto-merging tests/composer/composer_store.test.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

[rmbh-odoo]

@robodoo r+