🐛(backend) use the configured token type in BaseJWTAuthentication

authenticate and authenticate_header hardcoded "Bearer" instead of
using the token type the backend is configured with. Setting
APPLICATION_JWT_TOKEN_TYPE, ADDONS_TOKEN_TYPE or USER_ACCESS_TOKEN_TYPE
to anything else made every token be ignored, since the Authorization
scheme never matched.

Store the token type on the backend and use it both to match the
Authorization header scheme (case-insensitively) and as the
WWW-Authenticate scheme.

src/backend/core/external_api/authentication.py

@@ -48,6 +48,7 @@ class BaseJWTAuthentication(authentication.BaseAuthentication):
 
         self.is_enabled = is_enabled
         self._token_service = None
+        self._token_type = token_type
 
         if not self.is_enabled:
             return
@@ -73,7 +74,10 @@ class BaseJWTAuthentication(authentication.BaseAuthentication):
 
         auth_header = authentication.get_authorization_header(request).split()
 
-        if not auth_header or auth_header[0].lower() != b"bearer":
+        if (
+            not auth_header
+            or auth_header[0].lower() != self._token_type.lower().encode()
+        ):
             # Defer to next authentication backend
             return None
 
@@ -159,7 +163,7 @@ class BaseJWTAuthentication(authentication.BaseAuthentication):
 
     def authenticate_header(self, request):
         """Return authentication scheme for WWW-Authenticate header."""
-        return "Bearer"
+        return self._token_type
 
     def authenticate_credentials(self, token):
         """Validate JWT token and return authenticated user.