feat(backend): Finish save report to database (#29)

fix(backend): Finish save report to database (#29 (closed)) (!27 (merged))

• Add function transformKeysToAnswers to transform the keys of the report to the students answers
• Add function addKeysNotIncluded to add a new category of answers the AI didn't include in the report answer
• Fine tune and change the prompts to english
• Add chat3_5Answer.json to save the answer from chat AI
• Change schemas to include new format of the report
• Change save report endpoint to be named /save_report and add error handling

How to test:

• Send student feedback saved in output.json through 127.0.0.1:8000/analyze_feedback endpoint to generate report
• Send example report through 127.0.0.1:8000/save_report endpoint (format is saved in save_report_format.json) to save report in database

Co-authored by: @julianao

Closes #29 (closed)