[MAINTENANCE] Replacing Mysql-Connector with PyMySQL

[PoojaKatariya1811]

Issue https://github.com/blackrock/interface-generator/issues/11

Description

Mysql-Connector is not compatible with the Apache License. The plan is to replace the mysql-connector with pymysql which is compatible.

Changes Made

1. Added config.properties.
2. Added mysql_sample.yml for reference.
3. Modified MysqlSource for pymysql change.
4. Changes in respective unit tests.
5. added the dependency of pymysql in requirement.txt.

Definition of Done

Before submitting this pull request, please ensure that the following criteria have been met:

• [x] All automated tests have passed successfully.
• [x] All manual tests have passed successfully.
• [ ] Code has been reviewed by at least one other team member.
• [x] Code has been properly documented and commented as needed.
• [x] All new and existing code adheres to our project's coding standards.
• [x] All dependencies have been added or removed from the project's README or other documentation as needed.
• [x] Any relevant documentation or help files have been updated to reflect the changes made in this pull request.
• [x] Any necessary database migrations have been run.

Testing Snapshots