`empty_string` field anymore
Use `take_last_by` instead of `split_string` in `dmenu/dmenu.cc`

  Override default handlers instead of connecting new signals
  Freeze/thaw grids when inserting apps
  Use `grab_focus` instead of `set_property`
nwgbar:
  Override default handler instead of connecting a signal
  Freeze/thaw grid when inserting apps
  BarEntry constructor now receives args by-value
  Move BarEntry constructor `bar/bar_tools.cc` -> `bar/bar_classes.cc`

Rewrite icon loading
Fix highlighting not appearing

Use `{freeze,thaw}_child_notify` when rebuilding grid

Only handle necessary keys, pass others into search entry
Use casefold instead of uppercase for string comparison

  Fix nwgbar not launching apps
`take_last_by`:
  Add missing return
  Fix incorrect index

  Fix searchbox omitting space
  Call `filter_view` on `signal_search_changed`, not all insertions
  Replace deprecated Gtk::Main with recommended Gtk::Application
  Remove obsolete `search_phrase` field
  Remove unused functions