[low code connectors] generate complete json schema from classes (#15647)

* draft: first pass at complete schema language generation and factory validator

* actually a working validator and fixes to the schema that went uncaught

* remove extra spike file

* fix formatting file

* Add method to generate the complete JSON schema of the low code declarative language

* add testing of a few components during schema gen

* pr feedback and a little bit of refactoring

* test for schema version

* fix some types that were erroneously marked as invalid schema

* some comments

* add jsonschemamixin to interfaces

* update tests now that interfaces are jsonschemamixin

* accidentally removed a mixin

* remove unneeded test

* make comment a little more clear

* update changelog

* bump version

* generic enum not enum class

* Add method to generate the complete JSON schema of the low code declarative language

* add testing of a few components during schema gen

* test for schema version

* update tests now that interfaces are jsonschemamixin

* accidentally removed a mixin

* remove unneeded test

* make comment a little more clear

* generic enum not enum class

* add generated json file and update docs to reference it

* verbage

Author: brianjlai