Update container resolution and type hints throughout the codebase

[theimerj]

• [x] Move from concrete implementations to interfaces when using automatic dependency injection
• [x] Use ::modelClass() or ModelManifest::get() to get the correct class name for models
• [x] Use App::make($modelClass) to get the right instance where suitable
• [x] Use model interfaces in Schemas
• [x] Use morph aliases as schema types (⚠️ Possibly a breaking change)
  • [x] in Schemas
  • [x] in RouteGroups
  • [x] in Resources