Clearing up: Motif Search Custom Structures/Motifs

[blackpan2]

Currently, search has a button for "Custom" but it does not clarify what type of custom files it accepts.

Since search allows for custom motifs and for custom structures to be included it would make sense to have two buttons with more clear text on each.

[blackpan2]

@smcintosh881 does "Custom" as it currently works split up the files between custom structures and custom motifs so that the endpoint receives the files in the way that it expects.