Refactor TextView options into shared TextViewOptions struct and extend platform support

- Moved Options definition to a new cross-platform target STTextViewSwiftUICommon
- Introduced TextViewOptions replacing per-platform Options type
- Added platform-specific options (e.g., smart dashes, text replacement)
- Updated AppKit and UIKit TextView wrappers to apply relevant settings
- Updated Package.swift to include new dependency on STTextViewSwiftUICommon