FAO: re-searches for the already selected flow measures

[NelisV]

Within getSearchResultsUsing(), exclude already included state

[KHardern]

When searching for an FIR in the 'FAO' field, the system searches for those already selected.

To replicate:
Serach for an FIR in the FAO field and select. Then search for a second, note the inclusion of the first one in the dropdown.

[AndyTWF]

@KHardern I'm not sure this is fixable - I've applied the change that should fix the issue, but for some reason the frontend always includes "selected" things in the search. One thing I can at least do is force things already selected to the bottom of the list. Is this worth it?