On GraphQL/REST API docs, introduce a dropdown to pick known servers

[charlesBochet]

Scope & Context

Improve the UX of GraphQL and REST APIs documentation.

Current behavior

Right now if you browse: https://docs.twenty.com/rest-api/core#/ or https://docs.twenty.com/graphql/core, you have the option to set your server URL.
The server URL is prefilled with the api.twenty.com production URL.

Expected behavior

We would like to have:

• a dropdown with "Production API" / "Demo API" / "Localhost" / "Other". (default Production API)
• a text input: filled with 'api.twenty.com' / 'api-demo.twenty.com' / 'localhost:3000' / ''. The text input should be disabled if something else than Other is selected in the dropdown.

[charlesBochet]

@Bonapara FYI, if you want to have a different approach

[Bonapara]

LGTM!