Replace context with api.

See merge request !57

The return data of this hooks needs to be polished when AuthContext will
be removed.

This keeps the user logged in after tab closing, since state is stored
in the server.

Refactoring to reservation page.

See merge request !55

Setup reservation for api compatibility.

See merge request !54

Feature/authorization/curry

See merge request !53

Fix/authorization

See merge request !51