Add Back an Edit Menu in Chatbar

James Grahamrequested to merge
work/nvrwhere/text_edit_menu into master

With moving to TextEdit to prevent freezing we no longer get an edit menu for free from QQC2 desktop style. This means we need to implement one ourselves.

This implements a menu which is a simplified version of the one for TextArea in QQC2 desktop style. This also removes chatbarsyntaxhighlighter as it was only doing spelling highlights and a plain Sonnet.SpellcheckHighlighter can do that just fine now.

Merge request reports