ifUsernameExists Middleware

[aaryankotharii]

@IEEE-VIT/enigma-backend if a user has not set a username yet, none of the backend routes shall be accessible by the user. please add the code to make sure this is in place.

[anshulagx]

I think this is already happening in individual controllers, do you want to make a middleware out of it?
@ShubhamPalriwala @varunmurpani @Sidarth-V

con will be an increased db call for all the route.

[ShubhamPalriwala]

Let's implement this as a middleware and remove it from the routes

[anshulagx]

merged to prod