Feat | Add OpenAPI documentation for OAuth2GroupApiController

[matiasperrone-exo]

Task:

Ref: https://app.clickup.com/t/86b8e6jrj

Endpoints:

Method	Endpoint	Method Name
GET,HEAD	api/v1/groups	getAll

[martinquiroga-exo]

LGTM

@matiasperrone-exo please add the clickup card link to this PR.

[caseylocker]

1. Move #[OA\Get] from the class to getAllSerializerType() — Follow the pattern in OAuth2UserApiController where the annotation sits on getAllSerializerType(), not on the class declaration.
2. Use the existing user_oauth2 security scheme instead of creating OAuth2GroupsSecurity — user_oauth2 already covers Groups. Add IGroupScopes::ReadAll and IGroupScopes::Write to the scopes in
   app/Swagger/Security/UsersOAuth2Schema.php and reference user_oauth2 in the endpoint annotation. Remove OAuth2GroupApiControllerSecuritySchema.php.
3. Document the lack of route middleware — GET /api/v1/groups has no middleware in routes/api.php. The description field should note this (e.g., "No route-level middleware enforcement; requires valid OAuth2 bearer
   token only.").