Adding LanguageTool support

This patch adds LanguageTool support in the Unit Metadata widget.
You can launch a LanguageTool verification by pressing Ctrl+J at the moment.
I will add a timer feature which will launch a check automatically after X seconds of inactivity.
This also fixes a %1 escaping i18n issue in a tooltip
And refactoring of UnitMetadata pology feature to make it independent from temporaryNotes.

BUG: 410068