Refactor Toolkit, Workspace and Resource provider API

[iMrShadow]

This PR improves the public API surface, internal structure and documentation.

Toolkit

• Renamed methods for clarity:
  • OpenObject/SaveObject -> Serialize/Deserialize
  • Added SerializeWithConfig/DeserializeWithConfig for metadata access
• Simplified parameters: Removed MetaStreamConfiguration parameter from main methods, which is now returned via tuple when needed
• Removed redundant overloads:
  • Non-generic object-based methods
  • Try variants (use nullable returns instead)
• Added AutoResolveSymbols to Configuration for automatic symbol resolution
• Added missing documentation

Resource Providers

• Fixed IsEnabled behavior across all providers
• Added missing documentation

Workspace

• Cleaner asset API:
  • LoadAsset returns nullable T
  • LoadAssetWithConfig returns tuple with metadata
• Added ExportAsset as counterpart to LoadAsset (supports file path, stream, custom config)
• Removed redundant methods:
  • All SaveObject/LoadObject variants
  • Non-generic object-based methods
  • Try variants
• Added AutoResolveSymbols for automatic symbol resolution
• Added Workspaces property (mirrors GameProfiles)
• Added missing documentation

Samples

• Updated example projects to demonstrate new API workflow