feat: Add header annotations for accurate API documentation (#9380)

This will help api packages like https://codeberg.org/Cyborus/forgejo-api to generate clients that expose the header information as well. Currently `forgejo-api` has to edit the swagger json to generate a client crate that knows about headers.

- Create separate response types for different endpoint behaviors
- CommitList: Base type with only X-Total-Count header
- CommitListWithPagination: For GetPullRequestCommits (pagination headers + X-Total-Count)
- CommitListWithLegacyPagination: For GetAllCommits (pagination headers + X-Total-Count + deprecated X-Total)
- ChangedFileList: Base type with only X-Total-Count header
- ChangedFileListWithPagination: For GetPullRequestFiles (pagination headers + X-Total-Count)

This ensures swagger documentation accurately reflects which headers each endpoint returns.

Reviewed-on: https://codeberg.org/forgejo/forgejo/pulls/9380
Reviewed-by: Gusted <gusted@noreply.codeberg.org>
Reviewed-by: Cyborus <cyborus@disroot.org>
Co-authored-by: Myers Carpenter <myers@maski.org>
Co-committed-by: Myers Carpenter <myers@maski.org>

modules/structs/user_app.go

@@ -19,7 +19,6 @@ type AccessToken struct {
 }
 
 // AccessTokenList represents a list of API access token.
-// swagger:response AccessTokenList
 type AccessTokenList []*AccessToken
 
 // CreateAccessTokenOption options when create access token