Add CMSA support flag to mock_uss

[BenjaminPelletier]

Is your feature request related to a problem? Please describe.
When mock_uss is involved as a normal participant in F3548 automated testing in an interoperability ecosystem where CMSA is not supported, currently, it will still attempt to perform CMSA operations. But, this attempt will fail because the auth server will not grant tokens with the CMSA scope, and mock_uss will correspondingly return 500 for the flight planning request (e.g., Declare non-conforming test step)

Describe the solution you'd like
When mock_uss is in an interoperability ecosystem that does not support CMSA, it should indicate NotSupported to a request involving CMSA operations. This would probably be configured per Locality, adding something like a uses_cmsa() method to the Locality base class.

Describe alternatives you've considered
Other ways of determining capabilities could be used -- for instance, mock_uss could be informed of what scopes it is authorized to obtain and work out capabilities relative to those.