Deprecate query string auth tokens (#28390) (#28430)

Backport #28390 by @jackHay22

## Changes
- Add deprecation warning to `Token` and `AccessToken` authentication
methods in swagger.
- Add deprecation warning header to API response. Example: 
  ```
  HTTP/1.1 200 OK
  ...
  Warning: token and access_token API authentication is deprecated
  ...
  ```
- Add setting `DISABLE_QUERY_AUTH_TOKEN` to reject query string auth
tokens entirely. Default is `false`

## Next steps
- `DISABLE_QUERY_AUTH_TOKEN` should be true in a subsequent release and
the methods should be removed in swagger
- `DISABLE_QUERY_AUTH_TOKEN` should be removed and the implementation of
the auth methods in question should be removed

## Open questions
- Should there be further changes to the swagger documentation?
Deprecation is not yet supported for security definitions (coming in
[OpenAPI Spec version
3.2.0](https://github.com/OAI/OpenAPI-Specification/issues/2506))
- Should the API router logger sanitize urls that use `token` or
`access_token`? (This is obviously an insufficient solution on its own)

Co-authored-by: Jack Hay <jack@allspice.io>
Co-authored-by: delvh <dev.lh@web.de>

modules/setting/security.go

@@ -35,6 +35,7 @@ var (
 	PasswordHashAlgo                   string
 	PasswordCheckPwn                   bool
 	SuccessfulTokensCacheSize          int
+	DisableQueryAuthToken              bool
 	CSRFCookieName                     = "_csrf"
 	CSRFCookieHTTPOnly                 = true
 )
@@ -159,4 +160,11 @@ func loadSecurityFrom(rootCfg ConfigProvider) {
 			PasswordComplexity = append(PasswordComplexity, name)
 		}
 	}
+
+	// TODO: default value should be true in future releases
+	DisableQueryAuthToken = sec.Key("DISABLE_QUERY_AUTH_TOKEN").MustBool(false)
+
+	if !DisableQueryAuthToken {
+		log.Warn("Enabling Query API Auth tokens is not recommended. DISABLE_QUERY_AUTH_TOKEN will default to true in gitea 1.23 and will be removed in gitea 1.24.")
+	}
 }