feat: Add prompt verions REST route /prompts/{id}/versions

[anticorrelator]

• Lists all versions for a specific prompt

[cephalization]

I get errors on /prompts on this branch

pydantic_core._pydantic_core.ValidationError: 1 validation error for Prompt
name
  Input should be a valid string [type=string_type, input_value=Identifier(root='mycoolprompt'), input_type=Identifier]
    For further information visit https://errors.pydantic.dev/2.9/v/string_type

[cephalization]

This is unlike the prompt version endpoint which accepts a string id

[anticorrelator]

@cephalization whoops! fixed, thank you

[cephalization]

Hmm something about the name validation is unhappy

pydantic_core._pydantic_core.ValidationError: 1 validation error for Prompt
name
  Input should be a valid string [type=string_type, input_value=Identifier(root='test'), input_type=Identifier]
    For further information visit https://errors.pydantic.dev/2.10/v/string_type

I've tried wiping my db and a few names like test and tiny-prompt with the same issue.

This crops up on fetching all prompts or a prompt version. Maybe we need a rebase?