AprsParser should support APRS SPEC Addendum 1.2 Proposals

[CBielstein]

Description

AprsParser was developed against APRS PROTOCOL REFERENCE Protocol Version 1.0 then updated to APRS SPEC Addendum 1.1 with #74. The project should be extended to support APRS SPEC Addendum 1.2 Proposals, as appropriate.

Acceptance Criteria

• Verify if the APRS SPEC Addendum 1.2 Proposals were ever adopted as standard.
• AprsParser can decode any packets using APRS SPEC Addendum 1.2 Proposals packet formatting.