Refactoring performed for better code quality

[SanikaVT]

1. Extracted duplicate code from (printBorrowedBooks() and printOnHoldBooks()) to separate method in Borrower.java
2. Renamed variables in Person.java
3. Library.java contained all the methods related to Library operations and Database operations, Created two classes LibraryDatabase.java and LibraryOperations.java (both extend Library.java). LibraryOperations.java performs operations related to Library and LibraryDatabase.java performs only Database operations related to Library.

[harismuneer]

Hi @SanikaVT, appreciate your interest in refactoring the code. Can you kindly update the PR description with the changes you made and especially the context for those decisions? That would be quite helpful. Thanks

[SanikaVT]

Hi @SanikaVT, appreciate your interest in refactoring the code. Can you kindly update the PR description with the changes you made and especially the context for those decisions? That would be quite helpful. Thanks

Hi, please see the above description. Appreciate your reply!

[harismuneer]

@SanikaVT thank you for the description!

Below are some suggestions:

1. I recently merged a PR from @guryashdhall. Can you kindly update your PR and resolve any merge conflicts?
2. Can you add a note about the new classes below the UML diagram in Readme.md?
3. Can you re-test the application thoroughly to ensure no breaking changes are introduced in this PR?
4. Can you get this PR reviewed by at least 1 of your peers since this repository is used by many learners so the goal is to ensure the integrity and right coding patterns?