Connected Devices: Mouse, Touchpad and Keyboard

-Resolve some issues.
-Added the connected devices code in the main window.
-Replace BUTTON_DEFAULTS and BUTTON_REVERT with kMsgDefaults and kMsgRevert.

Change-Id: I3b0c86fc581056859239df0fbf2c085b8d168136
Reviewed-on: https://review.haiku-os.org/c/haiku/+/1619
Reviewed-by: Adrien Destugues <pulkomandy@gmail.com>