Allow fixing fine / coarse axis
Allows fixing either the fine or coarse movement axes in the 2d view.
- Fixing fine always moves with the coarse (stepper) axis and centres on fine (piezo) to scan.
- Fixing the coarse axis only allows movement with the fine range. Errors are raised if movement outside this range is attempted
UI in daiquiri-ui!643 (merged)
Edited by Stuart Fisher