ContextMenu: Assorted fixes and improvements
Replace broken bindings with active: true in both Loaders and Sonnet.SpellcheckHighlighter in TextArea.qml and natigate to "Text Field" page in Kirigami Gallery to test.
Show "Select All" menu item for password fields as well
There's no reason not to. User might want to select all text to delete it, for example, and they can already do so via shortcut.
Fix null object access in spellchecker menu item
It used to react to the wrong signal when spellcheckhighlighter becomes null, at which point spellcheckhighlighterLoader was also gone. Use explicit signal that is only emitted through actual user interaction.
Add menu separator between suggestions list and Add/Ignore
Rename "Enable Spellchecker" check box menu item to "Spell Check"
The latter sounds more professional, widespread, and isn't redundant for being a check box.