Cut'n'paste of a sequence segment into the Find dialog doesn't work

Somewhere around commit:136c0793b90b72b928c4d77dc109dd5c644e00d3 (NCList work for JAL-2446 - merging in the 'Cacheable' text input box work) we lost the critical line implementing the final step of JAL-49 - recognise when the user has pasted a sequence alignment file into the Find dialog and process it to extract the ungapped sequence content to use as a search query.