feature(backups): a graphql call to invalidate cache

selfprivacy_api/backup/__init__.py

@@ -269,6 +269,10 @@ class Backups:
 
         return snap
 
+    @staticmethod
+    def force_snapshot_reload():
+        Backups.sync_all_snapshots()
+
     @staticmethod
     def sync_all_snapshots():
         upstream_snapshots = Backups.provider().backuper.get_snapshots()

selfprivacy_api/graphql/mutations/backup_mutations.py

@@ -90,3 +90,9 @@ class BackupMutations:
         restore_snapshot(snap)
 
         return GenericJobMutationReturn()
+
+    @strawberry.mutation(permission_classes=[IsAuthenticated])
+    def force_snapshots_reload(self) -> GenericMutationReturn:
+        """Force snapshots reload"""
+        Backups.force_snapshot_reload()
+        return GenericMutationReturn()