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,