Allow SC to unlink existing FA from a club

[bhawesh96]

Is your feature request related to a problem? Please describe.
There are cases when the FA of a club changes. The existing FA needs to be unassigned, removed from DB entirely and the new FA has to sign up.

Describe the solution you'd like
Build a feature for the SC which allows them to unlink an existing FA from a club. After this, it is same as a new club who's FA hasn't signed up yet.

Additional Context
This might require writing some backend code as well. Please create corresponding issue in the backend if need be.

[bhawesh96]

Ideal solution would be to provide an option to the CLUB itself to be able to unlink existing FA and on doing this, a request goes to the SC. If SC approves, the FA is now unlinked and it's existence deleted from the firebase entirely (auth + db).
Now, club asks its new FA to sign up and the FA sign up process kicks in as usual.

I'm not sure if we're displaying the club-id anywhere in the club's profile. Club will need to provide the club-id to the new FA for the new FA to sign up.