Enable FxCop in AprsParserUnitTests directory

[CBielstein]

Description

Follows up on #60 to enable FxCop in the AprsParserUnitTests. Part of #27.

Changes

• Enables FxCop in the AprsParserUnitTests project
• Switches test methods to reuse code with inline data
• Renamed PacketUnitTests.cs to PacketInformationFieldUnitTests.cs to segment from future tests and keep test file sizes lower
• Added some more specific skip messages in a few test methods linking to new issues in GitHub
• Fixed one bug in decoding a comment on a maidenhead packet that was revealed while refactoring tests
• Other fixes

Validation

• Build passes (dotnet build -c Release at the root)
• Tests pass (dotnet test at the root)