[Bug] Duplicate logic in /src/controllers/authController.js

[gbowne1]

The original has;

• nested try catch blocks which are unnecessary and caused unreachable code

• duplicated register and login logic

• user declared twice in nested scope

• has mismatched braces due to a possible previous merge conflicts

• Missing JWT secret check in some branches

• 444 is not a valid HTTP status.

[gbowne1]

This issue will be closed by #117