71 implement book reserving

[DenisGithuku]

Description

Integrates book reserving.

Related Issue

Closes #71

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)

Testing Details

Simulates book reserving and unreserving in both home and detail viewmodels. Uses fakes that mutate objects in memory and expose streams.

• Tests passed
• Tests added

Checklist

• My code follows the style guidelines of this project.
• I have performed a self-review of my own code.
• I have commented my code, particularly in hard-to-understand areas.
• I have made corresponding changes to the documentation.
• My changes generate no new warnings.
• I have added tests that prove my fix is effective or that my feature works.
• New and existing unit tests pass locally with my changes.
• Any dependent changes have been merged and published in downstream modules.