feat: add command to pair lighthouse devices #12

There should be a command like axr lh pair for pairing lighthouse devices without needing to use lighthouse_console.

This could use:

1. lighthouse_console with async jobs: slower, but could be implemented now
2. lhctl when it is released publicly: significantly faster, but won't be ready for a while

I'd appreciate any feedback on which I should implement. I might end up going with option 1 now, then switch to 2 when lhctl is released.