UX follow-ups from "Resolve "[Frontend] Allow filtering compliance violations by branch""

The following discussion from !117948 (merged) should be addressed:

• @xanf started a discussion: (+1 comment)

  @cam.x considering quite intense discussion in !117942 (merged) could you please review this one (my concerns are that using "live search" might be quite heavy for this report, so we might want a follow up replacing to "search by click" pattern since this is first free type field here)

"search by click" pattern is ok; let's use the same search field as in the framework page then. The search icon should be a button.

Additionally with changing this pattern we would like to alter empty state message, it should state

• "No violations found" if no target branch filter is applied
• "No violations found. Change search options and try again" if target branch filter was applied

(source: #358412 (comment 1360552229))