Add support for controller AKAI APC Key25 Mk2

[alex-cherg]

Based on:

• previous work by @rcaneill in https://github.com/openAVproductions/openAV-Luppp/blob/master/resources/controllers/akai_apc_key25.ctrl for Mk1
• and AKAI APC Key25 Mk2 communication protocol

this PR adds support for Mk2 as well. There are two differences between the Mk1 and Mk2 files:

1. Output grid:clip_state MIDI messages in Mk2 are sent with status byte 150 in stead of 144 so that the grid buttons are being lit to 100% instead of 10%.
2. The colours are changed to be as close as possible to ones in the UI of Luppp by selecting from the colours supported by Mk2 in the communication protocol

			"state": {
				"empty": 0,
				"stopped": 96,
				"playing": 87,
				"recording": 72,
				"queueStopped": 78,
				"queuePlaying": 78,
				"queueRecording": 78
			}

In addition the PR changes the suffix of Mk1 to .ctlr (instead of .ctrl) as Luppp expects them to be. Future suggestion: shall we make all of those to be .json so that files would be automatically recognised and formatted by code editors?