[MIGRATE] Add support for Custom Resources

[TheRealAmazonKendra]

Tasks

• Update the generated schema to include service name information that we don't need to further parse in IR
• Update IR to either use import instructions directly from generated schema or use Custom resource handling (to be implemented)
• Add handling to look for the prefix 'Custom::<NAME_OF_CUSTOM_RESOURCE>' that does not rely on generated schema
  • Java
  • TypeScript
  • CSharp
  • Go(?)
  • Python
• Add end to end test cases for templates that include custom resources