Registering QActions for Ctrl+A/E/H/U/W kept colliding with Kate's own
actions (Select All, Close, …) — Qt reported ambiguous shortcuts and the
per-view shortcut-stripping sweep was fragile and incomplete.
Drop the QActions and the clearConflictingShortcuts machinery entirely.
Handle the keys in the application event filter: accept QEvent::ShortcutOverride
for our combos (so Kate's registered shortcut never fires) and act on the
following QEvent::KeyPress, consuming it. No shortcut is registered, so there
is nothing to be ambiguous with, and new views need no special handling.
All 5 ctest suites green.
bfbb32a95a