Fix KSP2 "PSI has changed since creation" errors

[elihart]

Summary

• Fixes critical crashes in KSP2 where accessing elements from previous processing rounds causes KaInvalidLifetimeOwnerAccessException: PSI has changed since creation
• This issue affects any project with multi-round annotation processing (deferred elements from round 1 accessed in round 2+)

Problem

In KSP2, PSI elements become invalid after each processing round. Epoxy's processor held references to stale KSP types/elements via:

• Cached XElement objects in KspResourceScanner
• XType stored in PackageModelViewSettings
• Lazy properties in GeneratedModelInfo, Type, and other classes
• Stale memoizer references captured in round 1, accessed in round 2+

Solution

Applied fixes across the processor:

1. Cache Invalidation: Added clearCachesForNewRound() to KspResourceScanner to clear element caches between rounds
2. Store Stable Identifiers: Changed PackageModelViewSettings to store defaultBaseModelClassName: String instead of XType
3. Pass Current Context: Updated method signatures throughout the codebase to accept currentMemoizer: Memoizer parameter instead of relying on stale captured references:
   - GeneratedModelInfo.isSuperClassAlsoGenerated()
   - GeneratedModelInfo.safeSuperClassElement()
   - GeneratedModelInfo.originatingElements()
   - GeneratedModelWriter.modelImplementsBindWithDiff()
   - ConfigManager.getDefaultBaseModel()
4. Fresh Type Resolution: Changed Memoizer.getMethodsReturningClassType() to accept classQualifiedName: String and resolve types fresh each round
5. Eager Initialization: Changed Type.kt's typeName and typeEnum from lazy to eager initialization to capture values when xType is still fresh
6. Exception Handling: Added try-catch in Memoizer.implementsModelCollector() for cases where XProcessing library has internal stale state