Cleanup: rename specials -> context_menu

In keeping with convention to match code & UI naming.

- No user visible changes.
- Include 'menu' in the name since context is an overloaded term.
- While a few of these are panels, from a user perspective they are
  still context menus.

release/scripts/startup/bl_ui/space_graph.py

@@ -324,7 +324,7 @@ class GRAPH_MT_delete(Menu):
         layout.operator("graph.clean", text="Clean Channels").channels = True
 
 
-class GRAPH_MT_specials(Menu):
+class GRAPH_MT_context_menu(Menu):
     bl_label = "F-Curve Context Menu"
 
     def draw(self, context):
@@ -379,7 +379,7 @@ class GRAPH_MT_snap_pie(Menu):
         pie.operator("graph.snap", text="Flatten Handles").type = 'HORIZONTAL'
 
 
-class GRAPH_MT_channel_specials(Menu):
+class GRAPH_MT_channel_context_menu(Menu):
     bl_label = "F-Curve Channel Context Menu"
 
     def draw(self, context):
@@ -430,8 +430,8 @@ classes = (
     GRAPH_MT_key,
     GRAPH_MT_key_transform,
     GRAPH_MT_delete,
-    GRAPH_MT_specials,
-    GRAPH_MT_channel_specials,
+    GRAPH_MT_context_menu,
+    GRAPH_MT_channel_context_menu,
     GRAPH_MT_pivot_pie,
     GRAPH_MT_snap_pie,
     GRAPH_PT_filters,