[Feature] Allow injecting non-external packages into @microsoft/api-extractor

## Issue

When using experimentalDts i would like to be able to set non-external packages, which is configured through api-extractor's "bundledPackages" option.
Currently it is not possible to pass any extra configuration into @microsoft/api-extractor.

## Possible solutions:

- Allow passing api-extractor config items through "experimentalDts" tsup's config option.

or
- Pass the content of tsup's "noExternal" into the "bundledPackages" api-extractor option.

or
- Detect the existence of an 'api-extractor.json' file, and pass it's content to api-extractor.

Start by tracing how experimentalDts is handled and how configuration reaches @microsoft/api-extractor. Compare the requested approaches around bundledPackages, noExternal, and api-extractor.json, then define and test one supported configuration path so non-external packages are included.

Written by the indexing model from the issue text.