Using .lower_bound and .upper_bound for location in forward fit gives wrong results

[Muriel23]

Short Description
When defining upper and lower bounds for the location of sources for the forward fit routine, the sources are placed at the wrong location. Routine with issue: stx_vis_fwdfit_pso.pro

The Screenshots show the problem:
The two images above are done with the current GSW version. The boxes show the chosen upper and lower boundaries. Forwardfit at the right does not give correct results.
The two images below are done with a corrected version of stx_vis_fwdfit_pso.pro, written by @annavolp. This gives correct results for the source locations.

The new routine from @annavolp should be merged with the GSW. (This is needed for imaging spectroscopy)

Environment

• STIX GSW Version (Nov. 2023)