Upgrade graphql and typescript dependencies

[jacopoRufini]

This PR was born to upgrade graphql-ws and apollo-client dependencies and became a fight with the dependency hell of javascript. What we did:

• updated the version of the library by a minor, we want the next version to be 0.9.0.
• updated the desired dependencies to latest: graphql-ws and apollo-client
• updated the undesired dependencies:
  • typescript, since apollo client was using internally some new features of the language
  • eslint, since it was outdated for the new typescript version
  • jest

Some dependencies had breaking changes so we managed to fix them in the most easy way.

• All the imports from '@apollo/client' were refactored in '@apollo/client/core, since the core part does not include React, and we were having problems importing react (that actually we don't need).
• src/subscription.ts now uses shouldRetry instead of isFatalConnectionProblem as a configuration to enable retries on fatal errors, since the latter is deprecated
• We fixed the type of V in the methods subscribe, createQuery, createMutation since the underlying library added some constraints on it