Generate Java mappings for OpenAPI-based types using Java code generator processing (so we get exact class/field/method names as generated code).

Property page for OpenAPI to TDL converter (with optional UI dependencies which hopefully don't break standalone mode)

- use schema name as generated package name
- add imports for Tdl and Http sub packages
- use Body as super type for structures (TODO make configurable)
- map JSON primitive types to corresponding Tdl predefined types

- use keyword list from grammar
- use appropriate names for reference and array types

- rolled back project configuration for model as OCL delegate setting does not seem to make a difference

* need new icon, need additional integration, in case also a wizard