[Versioning] Add tests for Perseus.renderability
[Versioning] Add tests for Perseus.renderability

Summary:
Adds test cases for Perseus.renderability.isItemRenderableByVersion.

Depends on D16249

Test Plan: `make test`!~

Reviewers: alex, emily

Reviewed By: emily

Differential Revision: https://phabricator.khanacademy.org/D16250

ariabuckles/perseus,ariabuckles/perseus,abe4mvp/perseus,daukantas/perseus,chirilo/perseus,daukantas/perseus,sachgits/perseus,sachgits/perseus,alexristich/perseus,abe4mvp/perseus,iamchenxin/perseus,alexristich/perseus,learningequality/perseus,ariabuckles/perseus,learningequality/perseus,ariabuckles/perseus,chirilo/perseus,iamchenxin/perseus