[RW-7610][risk=no] Unmount enzyme React components after each test case

[calbach]

Turns out there is no automated teardown of enzyme provided by our test harness after each test case, per enzymejs/enzyme#911

The solution described above caused some complications, as using a common DOM root caused an additional unmount on every mount() call within the same test case. It's possible that fixing the issues that arise there would be a more pure solution, but it would likely require retrofitting a bunch of our components.

Specifically, it would result in this error when attempting to reattach the component:

  console.error                                                                                                                                                                                 
    Warning: Can't perform a React state update on an unmounted component. This is a no-op, but it indicates a memory leak in your application. To fix, cancel all subscriptions and asynchronou
s tasks in a useEffect cleanup function.                                                                                                                                                        
        in Unknown (at with-error-modal.tsx:68)                                                                                                                                                 
        in ProfileErrorWrapper (at with-error-modal.tsx:45)                                                                                                                                     
        in ErrorModalWrapper (at data-access-requirements.spec.tsx:32)                                                                                                                          
        in Router (created by MemoryRouter)                                                                                                                                                     
        in MemoryRouter (created by WrapperComponent)                                                                                                                                           
        in WrapperComponent           

This change results in a large decrease in test latency for me locally and specifically reduced data-access-requirements test case runtime significantly, which were seemingly flaking due to large callback cruft build-up. From a few data points on circle appears to reduce test time by about half:

~2m50s -> ~1m20s

[jmthibault79]

This is awesome. Until now, I don't think my local UI test suite has fully passed since Angular. (Individual tests were fine, which makes sense)

[jmthibault79]

this appears to be unused

[jmthibault79]

no change when I comment this out

[calbach]

Oops, thanks. This was leftover from the previous approach

[calbach]

I've filed https://precisionmedicineinitiative.atlassian.net/browse/RW-7617 to track the ongoing Puppeteer notebook failures. These are completely unrelated to this PR, which only affects UI unit test code and has no bearing on the UI code itself, or the e2e tests.

[calbach]

(FYI I retried 4x, see https://app.circleci.com/pipelines/github/all-of-us/workbench?branch=ch%2Fui-test-deflake)