Animation: Add Slider operators to hotkey menu

Before that patch, the slider operators for the Graph Editor are not easily accessible since they don't have a hotkey.
This adds the "d" hotkey for the already existing slider operator menu.

Using the popup menu means that your last used operator will always be under the cursor, so it's quick to access.

Pull Request #104530

scripts/presets/keyconfig/keymap_data/blender_default.py

@@ -1817,6 +1817,7 @@ def km_graph_editor(params):
         ("graph.paste", {"type": 'V', "value": 'PRESS', "ctrl": True}, None),
         ("graph.paste", {"type": 'V', "value": 'PRESS', "shift": True, "ctrl": True},
          {"properties": [("flipped", True)]}),
+        op_menu("GRAPH_MT_slider", {"type": 'D', "value": 'PRESS'}),
         ("graph.previewrange_set", {"type": 'P', "value": 'PRESS', "ctrl": True, "alt": True}, None),
         ("graph.view_all", {"type": 'HOME', "value": 'PRESS'}, None),
         ("graph.view_all", {"type": 'NDOF_BUTTON_FIT', "value": 'PRESS'}, None),

scripts/startup/bl_ui/space_graph.py

@@ -332,7 +332,7 @@ class GRAPH_MT_slider(Menu):
 
     def draw(self, _context):
         layout = self.layout
-
+        layout.operator_context = "INVOKE_DEFAULT"
         layout.operator("graph.breakdown", text="Breakdown")
         layout.operator("graph.blend_to_neighbor", text="Blend to Neighbor")
         layout.operator("graph.blend_to_default", text="Blend to Default Value")