perf: make StaticPropertyInitializationGenerator incremental

[TimothyMakkison]

• Add PropertyWithDataSourceModel and associated types
• Return ImmutableArray<PropertyWithDataSource> from GetSemanticTargetForGeneration
• Move enabledProvider check to earlier in pipeline to reduce work
• ToUniquePropertyModels ensures that only distinct properties are converter into PropertyWithDataSourceModel
• Only call GetStaticPropertyDataSources instead of doing a unnecessary call in GenerateStaticPropertyInitialization

[TimothyMakkison]

• Fixed run length assertion in AotConverterTests
• Refactor and rename methods in the parse step
• Use a reusable properties list and keep track of already visited nodes
• Add tests to ensure that the generator is incremental

Method	Mean	Error	StdDev	Gen0	Allocated
RunGenerator	20.42 ms	0.354 ms	0.562 ms	250.0000	2.38 MB

Time and memory usage seems suspiciously low 🤔 but the tests appear to pass

[claude]

Code review

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

This is a well-structured performance optimization that properly implements incremental source generation patterns. The separation of parsing and generation phases, introduction of value-based model types, and proper use of EquatableArray all follow Roslyn best practices for incremental generators.