OpenApi import: Add client_id and client_secret variable

Currently when importing an OpenApi spec that contains OAuth 2 auth, fields like Client ID and Client Secret stay empty. It would be great if the app would fill them automatically with a vairable that I can configure for the different environments. This way I would not have to edit the Auth section for each request I want to use.

For instance Bruno automatically uses {{oauth_client_id}}, {{oauth_client_secret}}, {{oauth_state}}.

Also maybe have a import option to always use PKCE, as that also does not seem to be part of the OpenApi spec.