Add ability to start built-in cleaning modes

[jacobperron]

I think a subscriber listening to a custom cleaning mode message will be good. Then we will also need a way to stop/pause any active cleaning behaviours.

Proposal:

uint8 CLEAN_MODE_NONE=0
uint8 CLEAN_MODE_DEFAULT=1
uint8 CLEAN_MODE_MAX=2
uint8 CLEAN_MODE_SPOT=3

Header header
uint8 mode

Or maybe instead of CLEAN_MODE_NONE users could use another topic to change the mode out of PASSIVE #13

[jacobperron]

Added functionality to set-modes branch. Will merge after testing.