[algorithms][models] Return directly the queryset output for "used in" environments

No reason to return a tuple as the query is annotated.

This will allow easier use in the serialization part.

beat/web/algorithms/models.py

@@ -204,7 +204,7 @@ class Algorithm(Code):
         Returns:
 
           list: mapping environment to usage counts, determining how many times
-            a given algorithm has been successfuly used on that environment
+            a given algorithm has been successfully used on that environment
 
         """
 
@@ -213,27 +213,25 @@ class Algorithm(Code):
         from ..backend.models import Environment
 
         # Tries to figure through a maximum if an algorithm has been
-        # successfuly used inside an environment.
+        # successfully used inside an environment.
 
         # Case 1) The block is part of an experiment that was successful
         # Case 2) The block is part of an experiment that is not successful
         # (failed or other), but it is CACHED (if not cached, then we can't
         # attest anything about the algorithm/environment relationship!)
 
-        envs = (
+        return (
             Environment.objects.filter(
                 blocks__in=self.blocks.filter(
                     Q(experiment__status=Experiment.DONE)
                     | ((~Q(experiment__status=Experiment.DONE)) & Q(status=Block.DONE))
                 )
             )
-            .annotate(itemcount=Count("id"))
+            .annotate(use_count=Count("id"))
             .order_by("-creation_date")
             .distinct()
         )
 
-        return [(k, k.itemcount) for k in envs]
-
     # _____ Overrides __________
 
     def save(self, *args, **kwargs):