Log Message:
editors/featherpad: update to 1.3.4

A potential cause of crash is removed (by initializing the variables of
TextEdit and TabBar before any event is triggered).

Also:
● The Paste item of the Edit menu is enabled/disabled appropriately.
● The single quote is covered as the digit separator in C++(≥14) syntax
  highlighting.
● Enabled instant tooltips and corrected context menus on Wayland.