[FEAT] Interaction with quizzes: AI generation

[PavMash]

Feature description

Implement AI generation of quizzes, including file uploading on frontend (web first, but mobile as well), document parsing on backend and AI service integration.

What is needed to be done

• Integrate AI service with quiz core
• Implement document parsing (only pdf for now) to raw text
• Create quiz generating screen design for mobile and web in Figma
• Write web frontend with file uploading and receiving quiz, connect it to backend
• Write mobile frontend with all the same staff, connect it to backend

Acceptance Criteria

• Feature is fully working (end-to-end)
• Frontend corresponds to design
• High quality of code