Update Babel to support new TypeScript 3.7.2 syntax features

Created by: DillonFlohr

Is your proposal related to a problem?

When updating my projects TypeScript version to the new 3.7.2 and trying to use the new syntax, such as optional chaining:

foo?.bar()

I get an error during runtime saying that Babel does not support this feature:

Support for the experimental syntax 'optionalChaining' isn't currently enabled Add @babel/plugin-proposal-optional-chaining (https://git.io/vb4Sk) to the 'plugins' section of your Babel config to enable transformation.

Describe the solution you'd like

It would be nice if the Babel config made by CRA would install these new features. I do not want to have to eject to customize my Babel config.

Describe alternatives you've considered

I've tried installing the Babel plugin as described here with no luck: https://babeljs.io/docs/en/babel-plugin-proposal-nullish-coalescing-operator