Pass Image IDs to script when Wells selected. See #11835

Fixes https://trac.openmicroscopy.org.uk/ome/ticket/11835
When Wells are selected in HCS data and we launch a script that only takes Image IDs, we get the Image IDs from the wells and pass to script.

To test:
 - Select one or more wells
 - Launch script that takes Image IDs (E.g. Batch Image Export)
 - Check that IDs field is populated with correct Image IDs for the currently selected Field (and Data Type is "Image").
 - Check that a different Field gives different Image IDs in the script.