Input preferences: some style fixes.

Problems found by running haiku-format and looking at the resulting
files. Manually triaged to keep only the correct changes, currently
haiku-format is making a lot of unwanted changes as well.

Merging the correct changes allows us to see the incorrect ones more
easily and continue working on fixing them.

s/Haiku License/MIT License/g.

They are the same thing.

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>