Fix tr usage of UI strings

Fixing various problems ignored by MRs

• !5919 (merged)
  • Add few missing tr around strings
  • Fix HTML, parenthesis, etc around words (some translations units had HTML/C++ markup)
  • Fix Qt lupdate warnings (Classes without Q_OBJECT macro contained translatable strings in it, and lupdate could not get the correct context)
• #21593 : Fixing occurences of GetXMLLabel() used as identifier in code