Fix transcription link not being picked up correctly

[TimJentzsch]

Relevant issue: Closes #361

Description:

The OCR transcription got picked up instead of the user provided transcription. It doesn't have a link, so [Removed] was displayed in the check message instead.

We now filter the transcription author to make sure that the correct one is selected.

Additionally this adds a Γ character to the user gamma in the check message.

Checklist:

• [x] Code Quality
• [x] Pep-8
• [x] Tests (if applicable)
• [x] Success Criteria Met
• [x] Inline Documentation
• [ ] Wiki Documentation (if applicable)