/themes Integration into Telegram bot

[polinavishnev]

Have user input themes they would like to be tested on and base questions on those themes.

• [ ] Do ML stuff and ask the user to select some/all of the generated themes
• [x] Ask the user to input their own themes
• [x] Integrate the themes selected and typed by the user into the prompt for the OpenAI model
• [ ] Keep track of which question relates to which theme

[polinavishnev]

Smoothen the integration of ML:

• [x] Send the user a poll with proposed, found themes.
• [x] Ask the user to select the ones they would like.
• [x] Add the ones they are interested in into a bot.context.get['themes'].
• [ ] Ask if they would like to propose any themselves.
• [x] Add the ones they proposed through append.