GPencil: Revert commit d727f4f223 (Interpolate menu)

The menu is not redundant,  it is just another way to reach the tool and also give more discoverability of the operator shortcut (Many tools in Blender are also on menus, toolbar or header, just think of Move, Rotate, Scale).

There is also no reason to force the user/artist to change to edit mode for interpolate strokes, when the tool works perfectly in drawing mode too. It would only slow down the 2D animation workflow.

Reviewers: @mendio

release/scripts/startup/bl_ui/space_view3d.py

@@ -4392,6 +4392,7 @@ class VIEW3D_MT_paint_gpencil(Menu):
         layout = self.layout
 
         layout.menu("VIEW3D_MT_gpencil_animation")
+        layout.menu("VIEW3D_MT_edit_gpencil_interpolate")
 
         layout.separator()
 
@@ -4447,6 +4448,7 @@ class VIEW3D_MT_edit_gpencil(Menu):
         layout.separator()
 
         layout.menu("VIEW3D_MT_gpencil_animation")
+        layout.menu("VIEW3D_MT_edit_gpencil_interpolate")
 
         layout.separator()
 
@@ -4602,6 +4604,16 @@ class VIEW3D_MT_edit_gpencil_showhide(Menu):
         layout.operator("gpencil.reveal", text="Show All Layers")
 
 
+class VIEW3D_MT_edit_gpencil_interpolate(Menu):
+    bl_label = "Interpolate"
+
+    def draw(self, _context):
+        layout = self.layout
+
+        layout.operator("gpencil.interpolate", text="Interpolate")
+        layout.operator("gpencil.interpolate_sequence", text="Sequence")
+
+
 class VIEW3D_MT_object_mode_pie(Menu):
     bl_label = "Mode"
 
@@ -6634,6 +6646,7 @@ classes = (
     VIEW3D_MT_edit_armature_names,
     VIEW3D_MT_edit_armature_delete,
     VIEW3D_MT_edit_gpencil_transform,
+    VIEW3D_MT_edit_gpencil_interpolate,
     VIEW3D_MT_object_mode_pie,
     VIEW3D_MT_view_pie,
     VIEW3D_MT_transform_gizmo_pie,