Revert "UI: View3D Cursor Changes"

This change is yet to be followed by a more comprehensive design
proposal including:

* How to differentiate the modes apart.
* More clear definition of tools and the rules for their components (gizmo, cursor).
* Selection as a non-tool vs drag option.

This can be revisited for 2.90 with more time. For now the UI team
agrees to revert this.

--
This reverts commit 4aa703aa14.

release/scripts/startup/bl_ui/space_toolsystem_toolbar.py

@@ -137,7 +137,6 @@ class _defs_view3d_generic:
             idname="builtin.measure",
             label="Measure",
             description=description,
-            cursor='CROSSHAIR',
             icon="ops.view3d.ruler",
             widget="VIEW3D_GGT_ruler",
             keymap="3D View Tool: Measure",
@@ -375,7 +374,6 @@ class _defs_view3d_select:
             label="Select Lasso",
             icon="ops.generic.select_lasso",
             widget=None,
-            cursor='DEFAULT',
             keymap="3D View Tool: Select Lasso",
             draw_settings=draw_settings,
         )
@@ -400,7 +398,6 @@ class _defs_view3d_select:
             label="Select Circle",
             icon="ops.generic.select_circle",
             widget=None,
-            cursor='DEFAULT',
             keymap="3D View Tool: Select Circle",
             draw_settings=draw_settings,
             draw_cursor=draw_cursor,

source/blender/editors/space_view3d/space_view3d.c

@@ -1082,9 +1082,19 @@ static void view3d_main_region_message_subscribe(const struct bContext *C,
   }
 }
 
+/* concept is to retrieve cursor type context-less */
 static void view3d_main_region_cursor(wmWindow *win, ScrArea *area, ARegion *region)
 {
-  if (!WM_cursor_set_from_tool(win, area, region)) {
+  if (WM_cursor_set_from_tool(win, area, region)) {
+    return;
+  }
+
+  ViewLayer *view_layer = WM_window_get_active_view_layer(win);
+  Object *obedit = OBEDIT_FROM_VIEW_LAYER(view_layer);
+  if (obedit) {
+    WM_cursor_set(win, WM_CURSOR_EDIT);
+  }
+  else {
     WM_cursor_set(win, WM_CURSOR_DEFAULT);
   }
 }

source/blender/editors/space_view3d/view3d_gizmo_navigate_type.c

@@ -536,9 +536,12 @@ static int gizmo_axis_test_select(bContext *UNUSED(C), wmGizmo *gz, const int mv
   return -1;
 }
 
-static int gizmo_axis_cursor_get(wmGizmo *UNUSED(gz))
+static int gizmo_axis_cursor_get(wmGizmo *gz)
 {
-  return WM_CURSOR_DEFAULT;
+  if (gz->highlight_part > 0) {
+    return WM_CURSOR_EDIT;
+  }
+  return WM_CURSOR_NSEW_SCROLL;
 }
 
 void VIEW3D_GT_navigate_rotate(wmGizmoType *gzt)