refactor(prompts): unify template format and language (#6403)

* refactor(prompts): unify template format

* migrate the frontend

* build openapi

* refactor python client

* refactor JS

* fix db

* run ruff

* fix tests

* cleanup

* more cleanup

* run ci on prompts

* ruff again

* more fixes to python tests

* restore PromptTemplateFormat

* ruff

* build openapi

* build client

* cleanup

* fix tests

* cleanup