Fix T82210: Animation, Bake Action cleanup

Make post-bake cleanup of the Bake Action operator optional, and disable
by default.

Previously Bake Action would do two things:
- Bake the Action
- Clean up the FCurves

It is now possible (and even the default) to only perform the baking
operation.

Reviewed By: #animation_rigging, looch, sybren

Maniphest Tasks: T82210

Differential Revision: https://developer.blender.org/D9453

release/scripts/startup/bl_operators/anim.py

@@ -247,6 +247,11 @@ class NLA_OT_bake(Operator):
         "(useful for baking only part of bones in an armature)",
         default=False,
     )
+    clean_curves: BoolProperty(
+        name="Clean Curves",
+        description="After baking curves, remove redundant keys",
+        default=False,
+    )
     bake_types: EnumProperty(
         name="Bake Data",
         description="Which data's transformations to bake",
@@ -282,7 +287,7 @@ class NLA_OT_bake(Operator):
             do_visual_keying=self.visual_keying,
             do_constraint_clear=self.clear_constraints,
             do_parents_clear=self.clear_parents,
-            do_clean=True,
+            do_clean=self.clean_curves,
         )
 
         if not any(actions):