Enable optional-chaining & nullish-coalescing in preset-env

[reznord]

Do you want to request a feature or report a bug?
Feature

What is the expected behaviour?
Support babel stage 3 features in preact-cli

If this is a feature request, what is motivation or use case for changing the behaviour?
Right now, we can use optional-chaining with preact-cl@rc since we don't support them in our babel config.

Please mention other relevant information.
By setting shippedProposals to true, we can use the following proposals in CLI

[reznord]

In current babel versions, shippedProposals defaults to true. But since we use preset-modules for generating esm build, we need to wait until next version of preset-env is released (after this PR is merged).

[eugenezastrogin]

PR in question seems to be merged quite some time ago.

[reznord]

This is fixed in 3.0.0-rc.14 with babel updates.