Use Alt-LMB to improve tool-access (when MMB emulation is used, we can't enable this).
- For LCS: Alt-LMB executes the tool without needing to use the gizmo.
(we keep drag threshold as it's needed for detecting selection).
- For RCS: Alt-LMB sets the cursor.
(this allows us to remove the drag threshold on LMB - it always activates tool immediately).
### Conflicts
- Regarding use of Alt-LMB.
- Grease pencil uses Alt-LMB, apparently these weren't essential (since they're already not accessible with MMB-emulation enabled).