Data: Refactor and optimize withSelect, withDispatch handling of registry change

[aduth]

This pull request seeks to refactor the implementations of withSelect and withDispatch to avoid dependency upon -- and thus enable the deprecation of -- the remountOnPropChange higher-order component.

A few notes as to the rationale:

• remountOnPropChange used broadly outside this specific context could serve as a "footgun", since it can have negative effects in focus loss (example)
• Higher-order components are considered to be performance-impacting (reference). withSelect and withDispatch are two of the hottest code paths, and as implemented prior to these changes would each have a remountOnPropChange wrapper
• The remountOnPropChange wrapper for withDispatch is actually not necessary, due to its behavior of proxying function calls to resolve registry.dispatch only when the mapped prop is called.

Testing Instructions:

This is a refactoring change. There should be no impact on usage.

Ensure unit tests pass:

npm run test-unit packages/data

[youknowriad]

I don't like that we're doing this magic in shouldComponentUpdate. It doesn't seem like the best function for this kind of side effects. Ideally it's componentWillReceiveProps but this one has been deprecated, so not sure what's the "good" approach for these at the moment.

I see shouldComponentUpdate as a function that can be called multiple times by React even without rendering (especially in async) as it's supposed to be a pure function just returning a boolean.

[aduth]

My general approach with these components has been to happily throw out all best practices if it means performance could suffer even marginally in the individual case by following them.

If there's an unexpected behavior that could occur in how we're implementing (even "number of calls"), we should have a unit test to cover it in whatever fix need to be made.

[youknowriad]

Makes sense 👍

[youknowriad]

LGTM 👍 The e2e tests spoke for this :P

There's a small unit test breakage to fix and rebase

[aduth]

Pushed rebased branch.

Including two issues to have been resolved:

• Remove remaining unused reference to remountOnPropChange in with-dispatch/index.js
• Update tests for remountOnPropChange to expect the deprecated call