Add `setTally` method for DevolayReceiver

[nocarryr]

I implemented NDIlib_recv_set_tally and added the appropriate public methods (at least as best as I could figure out how to).

Tested the build on some NDI devices and it appears to be working properly. Please let me know if there's a different method signature you would rather have (and if the constructor for DevolayTally needs to remain private).

The CI build may fail without the changes in #29 btw