fix mavlink codegen enum methods (bluenviron#47)

Refactored MarshalText, UnmarshalText, and String methods for Enum types.

Co-authored-by: sirno-baka <[email protected]>

change repository owner (bluenviron#44)

add options to set timeouts (bluenviron#40)

(automatic) update dialects to rev https://github.com/mavlink/mavlink…

…/tree/2bdcab78b53d1e349079b43c9d726036abe0617c

improve documentation of examples

improve tests