chore: Override OAuth2AuthenticationException to differentiate the errors thrown by Appsmith (#35160)

## Description
> Extend OAuth2AuthenticationException so that we can differentiate
between AppsmithException and exceptions thrown by Spring Library.
> There is not going to be any change to the Authentication flows here,
as the we are just inheriting the OAuth2AuthenticationException.


Fixes #`Issue Number`  
_or_  
Fixes `Issue URL`
> [!WARNING]  
> _If no issue exists, please create an issue first, and check with the
maintainers if the issue is valid._

## Automation

/ok-to-test tags="@tag.All"

### 🔍 Cypress test results
<!-- This is an auto-generated comment: Cypress test results  -->
> [!TIP]
> 🟢 🟢 🟢 All cypress tests have passed! 🎉 🎉 🎉
> Workflow run:
<https://github.com/appsmithorg/appsmith/actions/runs/10092949232>
> Commit: bc2f204
> <a
href="https://internal.appsmith.com/app/cypress-dashboard/rundetails-65890b3c81d7400d08fa9ee5?branch=master&workflowId=10092949232&attempt=2"
target="_blank">Cypress dashboard</a>.
> Tags: `@tag.All`
> Spec:
> <hr>Thu, 25 Jul 2024 13:13:00 UTC
<!-- end of auto-generated comment: Cypress test results  -->


## Communication
Should the DevRel and Marketing teams inform users about this change?
- [ ] Yes
- [ ] No


<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit


- **New Features**
- Introduced a new custom exception for improved handling of OAuth 2.0
authentication errors, enhancing the clarity and robustness of the
authentication process.
  
- **Bug Fixes**
- Enhanced error categorization in the authentication process by
refining the error handling logic, allowing for better management of
exceptions related to OAuth 2.0.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

---------

Co-authored-by: Nilesh Sarupriya <[email protected]>

Author: nsarupr

app/server/appsmith-server/src/main/java/com/appsmith/server/authentication/handlers/ce/CustomOAuth2UserServiceCEImpl.java

@@ -3,13 +3,16 @@
 import com.appsmith.server.domains.LoginSource;
 import com.appsmith.server.domains.User;
 import com.appsmith.server.domains.UserState;
+import com.appsmith.server.exceptions.AppsmithException;
+import com.appsmith.server.exceptions.AppsmithOAuth2AuthenticationException;
 import com.appsmith.server.repositories.UserRepository;
 import com.appsmith.server.services.UserService;
 import lombok.extern.slf4j.Slf4j;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.security.oauth2.client.userinfo.DefaultReactiveOAuth2UserService;
 import org.springframework.security.oauth2.client.userinfo.OAuth2UserRequest;
 import org.springframework.security.oauth2.core.OAuth2AuthenticationException;
+import org.springframework.security.oauth2.core.OAuth2Error;
 import org.springframework.security.oauth2.core.user.OAuth2User;
 import reactor.core.publisher.Mono;
 
@@ -65,6 +68,12 @@ private Mono<User> checkAndCreateUser(OAuth2User oAuth2User, OAuth2UserRequest u
                         return repository.save(user);
                     }
                     return Mono.just(user);
-                });
+                })
+                .onErrorMap(
+                        AppsmithException.class,
+                        // Throwing an AppsmithOAuth2AuthenticationException in case of an AppsmithException
+                        // This is to differentiate between Appsmith exceptions and OAuth2 exceptions
+                        error -> new AppsmithOAuth2AuthenticationException(
+                                new OAuth2Error(error.getAppErrorCode().toString(), error.getMessage(), "")));
     }
 }

app/server/appsmith-server/src/main/java/com/appsmith/server/authentication/handlers/ce/CustomOidcUserServiceCEImpl.java

@@ -4,6 +4,7 @@
 import com.appsmith.server.domains.User;
 import com.appsmith.server.domains.UserState;
 import com.appsmith.server.exceptions.AppsmithException;
+import com.appsmith.server.exceptions.AppsmithOAuth2AuthenticationException;
 import com.appsmith.server.repositories.UserRepository;
 import com.appsmith.server.services.UserService;
 import lombok.extern.slf4j.Slf4j;
@@ -76,7 +77,9 @@ public Mono<User> checkAndCreateUser(OidcUser oidcUser, OidcUserRequest userRequ
                 })
                 .onErrorMap(
                         AppsmithException.class,
-                        error -> new OAuth2AuthenticationException(
+                        // Throwing an AppsmithOAuth2AuthenticationException in case of an AppsmithException
+                        // This is to differentiate between Appsmith exceptions and OAuth2 exceptions
+                        error -> new AppsmithOAuth2AuthenticationException(
                                 new OAuth2Error(error.getAppErrorCode().toString(), error.getMessage(), "")));
     }
 }

app/server/appsmith-server/src/main/java/com/appsmith/server/exceptions/AppsmithOAuth2AuthenticationException.java

@@ -0,0 +1,29 @@
+package com.appsmith.server.exceptions;
+
+import lombok.Getter;
+import org.springframework.security.oauth2.core.OAuth2AuthenticationException;
+import org.springframework.security.oauth2.core.OAuth2Error;
+
+@Getter
+public class AppsmithOAuth2AuthenticationException extends OAuth2AuthenticationException {
+
+    private final OAuth2Error error;
+    /**
+     * Constructs an {@code AppsmithOAuth2AuthenticationException} using the provided parameters.
+     * @param error the {@link OAuth2Error OAuth 2.0 Error}
+     */
+    public AppsmithOAuth2AuthenticationException(OAuth2Error error) {
+        this(error, error.getDescription(), null);
+    }
+
+    /**
+     * Constructs an {@code AppsmithOAuth2AuthenticationException} using the provided parameters.
+     * @param error the {@link OAuth2Error OAuth 2.0 Error}
+     * @param message the detail message
+     * @param cause the root cause
+     */
+    public AppsmithOAuth2AuthenticationException(OAuth2Error error, String message, Throwable cause) {
+        super(error, message, cause);
+        this.error = error;
+    }
+}