Invalid setJwt method location

[scottinet]

The setJwt method currently belongs to the Auth class, but it should instead be put in the Kuzzle class, as stated by the other languages documentation (see the jwt property in the JS Kuzzle constructor documentation)

This is especially visible as the C++ documentation shows the JWT getter in the Kuzzle ctor documentation: https://docs-v2.kuzzle.io/sdk-reference/cpp/1/kuzzle/introduction/