Fix pending point extraction in gen_multi_from_multi (#2914)

Summary:

Earlier today danielcohenlive was having trouble using gs and was getting a weird modeling error. Lena did some investigation an found we were using the wrong method to grab pending points from the experiment. See her notebook in the test plan for more details. to quote "Basically in some settings it’s not safe to deem a point pending based on the trial status; generally no point for which we have data, we want to consider pending"

I just am putting up the fix with her logic here

Differential Revision: D64563496

ax/modelbridge/generation_strategy.py

@@ -21,10 +21,7 @@
 from ax.core.generation_strategy_interface import GenerationStrategyInterface
 from ax.core.generator_run import GeneratorRun
 from ax.core.observation import ObservationFeatures
-from ax.core.utils import (
-    extend_pending_observations,
-    get_pending_observation_features_based_on_trial_status,
-)
+from ax.core.utils import extend_pending_observations, extract_pending_observations
 from ax.exceptions.core import DataRequiredError, UnsupportedError, UserInputError
 from ax.exceptions.generation_strategy import (
     GenerationStrategyCompleted,
@@ -549,10 +546,7 @@ def gen_for_multiple_trials_with_multiple_models(
         """
         trial_grs = []
         pending_observations = (
-            get_pending_observation_features_based_on_trial_status(
-                experiment=experiment
-            )
-            or {}
+            extract_pending_observations(experiment=experiment) or {}
             if pending_observations is None
             else deepcopy(pending_observations)
         )

ax/service/tests/scheduler_test_utils.py

@@ -31,7 +31,10 @@
 from ax.core.objective import Objective
 from ax.core.optimization_config import OptimizationConfig
 from ax.core.runner import Runner
-from ax.core.utils import get_pending_observation_features_based_on_trial_status
+from ax.core.utils import (
+    extract_pending_observations,
+    get_pending_observation_features_based_on_trial_status,
+)
 from ax.early_stopping.strategies import BaseEarlyStoppingStrategy
 from ax.exceptions.core import OptimizationComplete, UnsupportedError, UserInputError
 from ax.exceptions.generation_strategy import AxGenerationException
@@ -1783,9 +1786,9 @@ def test_batch_trial(self, status_quo_weight: float = 0.0) -> None:
         with patch(  # Record calls to functions, but still execute them.
             (
                 f"{self.PENDING_FEATURES_CALL_LOCATION_BATCH}."
-                "get_pending_observation_features_based_on_trial_status"
+                "extract_pending_observations"
             ),
-            side_effect=get_pending_observation_features_based_on_trial_status,
+            side_effect=extract_pending_observations,
         ) as mock_get_pending, patch.object(
             scheduler.generation_strategy,
             "gen_for_multiple_trials_with_multiple_models",