Osu: MIDI devices support

[lenzfilipski]

Describe the feature: Make compatible the use of midi devices directly, without third-party software.

Proposal designs of the feature:

• possibility of assigning the midi keys in "Key configuration"
• if possible, turn on the midi note/key set for better recognition by returning a signal to the note/key
• live light feedback when clicking
  

I've got a lot of fun playing osu! with my Launchpad S. Normally I use Bome's Midi Translator so I can use my Launchpad as a keyboard but it does'n work in osu!laser. So i got this idea.
Also sorry for my english.

[peppy]

Definitely needs to be added (I believe stable already had support).

[HoLLy-HaCKeR]

I previously looked into adding this to the framework, but the nuget package for ManagedBass.Midi does not expose the right methods (see ManagedBass/ManagedBass#54).

[HoLLy-HaCKeR]

Midi input is now in the framework since ppy/osu-framework#2804, so once we have a framework update it should work.