GUI: Icon selection not automatic in synoptic editor - Check behaviour and fix Timebox [1 day]

## Where?

Icon selection not automatic after clearing target OPI for new component in synoptic editor.

## How?

Discovered during manual system testing of IBEX release v15.0.0

## Reproducible?

Possibly. Check behaviour as described in manual system test below.

### To Reproduce

[manual system test](https://github.com/orgs/ISISComputingGroup/projects/21/views/3?pane=issue&itemId=74591121)

## Acceptance criteria
- [ ] behaviour is investigated
- [ ] corrected if problem found

## How to Test
See link in 'To Reproduce' section above

### Discussed in planning 05/09/24
19:35