Support additional nmea messages

[SpangeJ]

Write parsers and tests for new NMEA messages:

• HDT
• DPT
• PTNL,GGK
• XDR
• AML,SVM

[dotMorten]

Dpt, Xdr and Hdt (the latter being deprecated) are the only ones part of the NMEA spec.
The others seem to rely on an odd Trimble pattern that I think would require some adjustments to the underlying library for how messages like that are being identified since they rely on multiple columns. I'm not really in favor of hardcoding those into the message parser, but would prefer you first open an discussing the need for parsing messages like that, and then probably keep these messages locally as message extensions in the application and not in the NMEA library itself.

[dotMorten]

According to the NMEA spec HDT is a deprecated message

[SpangeJ]

Do you which me to revert it?
I can just create it locally in my project if you think it should not be part of this library.

[dotMorten]

Is this really how a real world message looks with the -- prefix and no talker-id?

[SpangeJ]

Yes, my data looks like that.

[SpangeJ]

Dpt, Xdr and Hdt (the latter being deprecated) are the only ones part of the NMEA spec. The others seem to rely on an odd Trimble pattern that I think would require some adjustments to the underlying library for how messages like that are being identified since they rely on multiple columns. I'm not really in favor of hardcoding those into the message parser, but would prefer you first open an discussing the need for parsing messages like that, and then probably keep these messages locally as message extensions in the application and not in the NMEA library itself.

I agree with your reasoning. PTNL,GGK and AML,SVM are different since they rely on the two first part of the message in order to identify what kind of message it is.

I will remove them from this PR.
I should solve the Trimble pattern properly in a separate PR. I'll open a discussion prior to that PR.