Add configuration for raising containers on focus

* New configuration option: raise_floating
  (From the discussion on https://github.com/i3/i3/issues/2990)
* By default, it still raises the window on focus, otherwise it
  will raise the window on click.

sway/meson.build

@@ -48,6 +48,7 @@ sway_sources = files(
 	'commands/floating_modifier.c',
 	'commands/focus.c',
 	'commands/focus_follows_mouse.c',
+	'commands/raise_floating.c',
 	'commands/focus_on_window_activation.c',
 	'commands/focus_wrapping.c',
 	'commands/font.c',