Feature cn 9 step1

[mandolyte]

Note! this does not cover issue 9 to bring file fetching logic into app. It does the following:

• cuts dependency on CV package for doing book packages. This code is now in the app with same name under src/core
• copied over the gitApi.js from the CV package and updated as needed

This refactor does the bare minimum and allows us to continue to evolve the caching/fetching to improve performance.

I have checked the boxes on issue #9 to reflect how much this PR covers.

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This change is