E2e whiteboard

[treystevens]

Description

• Adding e2e whiteboard tests for Zwibbler
• Some of the tests have false-positive due to limitations of the third-party module being unable to detect pixel differences between two photos. Undo, redo, and clear whiteboard tools are passing no matter what threshold of pixel difference is given.
• Made a few patch changes to a dependency to get it to work nicely with where we are storing our screenshots.

*Note: This implementation of tests is running a bit different than the visual regression tests that I have seen. It seems like most visual regression libraries first have you set a base snapshot of what your desired end state looks like and then run subsequent tests that take snapshots of the new end state and compare that to the base snapshot. The behavior that we have in our tests is that we are taking a base snapshot and taking another snapshot in the same test and comparing them right away.

Run npx cypress run --spec "tests/e2e/specs/whiteboard-tests.js" for quick testing

Developer self-review checklist

• [x] Potentially confusing code has been explained with comments
• [x] No warnings or errors have been introduced; all known error cases have been handled
• [x] Any appropriate documentation (within the code, README.md, docs, etc) has been updated
• [x] All edge cases have been addressed