Exporting a selector out of a library complains of Dictionary cannot be named

[ymcnicoll]

I'm submitting a...

[ ] Regression (a behavior that used to work and stopped working in a new release)
[X] Bug report  
[ ] Feature request
[ ] Documentation issue or request

What is the current behavior?

When compiling a library using Ng-Packagr I get errors from un-exported types used by selectors. I dont get this error if using Reselect to create selectors.

Part of the issue is caused by Entity using un-exported Dictionary type for its entities.

Expected behavior:

Compiling without errors

Minimal reproduction of the problem with instructions:

1. create a project following sample from ng-packagr.
2. create module withing the project with feature and selectors
3. build

Other information:

[peterbsmyth]

@ymcnicoll would you provide a stackblitz or repo or similar example to reproduce then I can PR for you.