Adds exported types to moduleResolution:node16

[dmihalcik-virtru]

This will let users get type information when compiling ESM projects with node module settings in later versions of tsc and node 18+

[google-cla[bot]]

Thanks for your pull request! It looks like this may be your first contribution to a Google open source project. Before we can look at your pull request, you'll need to sign a Contributor License Agreement (CLA).

View this failed invocation of the CLA check for more information.

For the most up to date status, view the checks section at the bottom of the pull request.

[dmihalcik-virtru]

Notably, without this line I'll get the following error when trying to build my project (node 18, tsconfig with module: CommonJS, moduleResolution: node16, package.json with type: module), so maybe not a common configuration but what I'm doing :-0