Fix Loading State for Transcriptions

[delexagon]

Summary
The transcriptions show 'no transcription for ...' before being loaded to the browser. This should instead indicate that transcriptions are loading.

Work Detail

• Change string when transcripts are currently loading
• Get rid of the intermediate step "no results for "" in transcript"
  This is mediated between components/hearing/HearingDetails.tsx and components/hearing/Transcriptions.tsx

Current State
Pull request #2015 handles part 1 - DO NOT work on this until it is merged to prevent a future conflict.