Add comprehensive tests and use pattern matching improvements

- Added WorkItem attribute to all attribute filtering tests
- Added tests for all syntax node types (struct, interface, enum, delegate, record, constructor, property, field, event, parameter, type parameter, indexer)
- Added tests for all target specifiers (assembly, module, type, method, field, property, event, param, return, typevar)
- Simplified AttributeUsageAttribute lookup using nested property pattern
- Simplified constructor argument check using collection pattern
- Changed target identifier check to use SyntaxKind instead of string literals

Co-authored-by: CyrusNajmabadi <[email protected]>

Author: Copilot