Add_MySQL_Connection_Pool_with_Environment_Variable_Support

[smog-root]

Issue_id: (NOT CREATED)!

Changes:

• Added logic to test the connection upon initialization and release it back to the pool.
• Included specific error messages for common database connection issues.

Error Handling: Added error handling logic to manage common database connection errors such as connection loss, too many connections, or connection refusal. Errors are logged with appropriate messages to help with debugging.

How to Test:

1. Ensure that .env file contains the correct database credentials (host, user, password, etc.).
2. Run the application and check if it successfully connects to the database.
3. Verify that the pool manages multiple connections efficiently under load.
4. Check error logs when database connections fail to ensure proper handling and logging.

Note: I did not created an issue so. Assign me this PR, and add gssoc-ext with level3, hacktoberfest-accepted labels!

@Harshdev098

[smog-root]

dude are you going to merge it??