feat: Add shared languages as a bonus during matching process

[JeangelLF]

Ticket

Resolves https://github.com/corona-school/project-user/issues/1553

What was done?

• Included a bonus for shared languages in the matching-algo
• Updated tests

[Jonasdoubleyou]

I wonder whether this has any effect at all - is there any realistic language overlap? Do we have many users that have maintained other languages?

[JeangelLF]

I wonder whether this has any effect at all - is there any realistic language overlap? Do we have many users that have maintained other languages?

With the new registration flow the new users can now indicate which languages they speak or can help with. We’ve also added a language update step in the match request process on the user app, so profiles stay up to date. The hope is that this will have a bigger impact, especially for pupils who don’t speak German.

[Jonasdoubleyou]

For it to have a bigger impact it has to be a constraint (causing the inverse effect that users stay in the pool for a long time) - the score is more or less useless as the number of users in the pool is low