say NO to try-catch in controllers

- added ExceptionsMiddleware.cs
- added more Exception types
- removed all exceptions logic in controllers

SurveyBackend/SurveyBackend.Services/Services/AuthorizationService.cs

@@ -16,12 +16,12 @@ public class AuthorizationService : IAuthorizationService
         _passwordHasher = passwordHasher;
     }
 
-    public async Task<string?> LogInUser(string email, string password)
+    public async Task<string> LogInUser(string email, string password)
     {
         var user = await _userService.GetUserByEmail(email);
-        if (user is null || !_passwordHasher.Verify(password, user.Password))
+        if (!_passwordHasher.Verify(password, user.Password))
         {
-            throw new UnauthorizedException("Email or password is incorrect.");
+            throw new UnauthorizedException("Password is incorrect.");
         }
 
         var token = TokenHelper.GetAuthToken(user);