Feat razor changes

[yovafree]

Purpose

• Changes to add books and book authors at the frontend level.
• General refactoring is performed and the API endpoint is centralized.

Does this introduce a breaking change?

[x] Yes
[ ] No

Pull Request Type

What kind of change does this Pull Request introduce?

[ ] Bugfix
[x] Feature
[x] Code style update (formatting, local variables)
[] Refactoring (no functional changes, no api changes)
[ ] Documentation content changes
[ ] Other... Please describe:

What to Check

Verify that the following are valid

• Add authors
• Add books
• Add book authors

[yovafree]

@microsoft-github-policy-service agree

[croblesm]

Thank you @yovafree for your contribution. I will be reviewing this PR in the upcoming days.