Polished auth flow including ReservedRoute and role selection.

src/api/setRole.ts

 import axios from 'axios';
 
 /**
- * Ask the server all the roles of an user (if the user has multiple roles).
- * @returns array of roles.
+ * Set the role of the user in the database.
  */
 export const setRole = async (role: string): Promise<void> =>
   axios.post('/api/web/login/set_role', { role });