fix: document and test PublicMethodMissingTestAttributeAnalyzer property/event handling

[thomhurst]

Summary

Closes #4863

• Investigated whether PublicMethodMissingTestAttributeAnalyzer produces false positives on property getters/setters and event handlers
• Finding: The existing MethodKind.Ordinary filter already correctly excludes these cases. In Roslyn's MethodKind enum, property accessors have MethodKind.PropertyGet/PropertySet and event accessors have MethodKind.EventAdd/EventRemove — all distinct from MethodKind.Ordinary
• Added a clarifying comment to the analyzer documenting this behavior
• Added 4 new test cases to explicitly verify no false positives for: properties (auto and explicit), events with custom accessors, override methods, and static methods

Test plan

• All new tests pass on net8.0 and net9.0
• Existing tests continue to pass
• dotnet build TUnit.Analyzers/TUnit.Analyzers.csproj succeeds

[claude]

Code review

No issues found. Checked for bugs and CLAUDE.md compliance.

The changes look clean and well-targeted:

• The clarifying comment added to PublicMethodMissingTestAttributeAnalyzer.cs accurately describes the semantics of MethodKind.Ordinary — property accessors (PropertyGet/PropertySet), event accessors (EventAdd/EventRemove), constructors, destructors, and operators all have distinct MethodKind values and are correctly excluded by the existing filter.
• All 4 new test cases (Property_Getter_Setter_No_Error, Event_Accessors_No_Error, Override_Method_No_Error, Static_Method_No_Error) align with the actual analyzer filter chain and correctly assert zero diagnostics.
• No CLAUDE.md rule violations (snapshot testing, dual-mode, AOT, no blocking async — none apply to this analyzer/test-only change).