fix: support modern package exports syntax

[louis-bompart]

What is the current behavior?

Currently, you cannot use packages that use modern module resolution based on subpath-exports in your Stencil Project^1. This is caused by the hard coding of Node10 for moduleResolution in Stencil.

GitHub Issue Number: #4229 (mitigation, not 💯 fix)

What is the new behavior?

Replace Node10 with Bundler. While it's not a "trivial" change, the impact for the end-user should be minimal (see Breaking change section)

Documentation

N.A.

Does this introduce a breaking change?

• [ ] Yes
• [x] No

I ran some 'health-check' (running stencil compiler with & without my changes on packages that use various ways of defining sub-packages), and all projects that worked without my changes worked with it as well, without changes.

Moreover, from the TypeScript reference documentation, I reckon it is safe to say that Bundler is akin to a "superset" of Node10: https://www.typescriptlang.org/docs/handbook/modules/reference.html#bundler https://www.typescriptlang.org/docs/handbook/modules/reference.html#node10-formerly-known-as-node

Testing

In addition to the existing test (npm test), I ran some san-check. We have a package that we are migrating from 'hackish subpackages' (using subdirectory and package.json in them) to subpath exports in a major version, I used this package as an example and did the following tests:

• Stencil 4.21.0 'vanilla' + hackish subpackages: ✅ compiling, behavior nominal
• Stencil 4.21.0 'patched' (i.e with my changes) + hackish subpackages: ✅ compiling, behavior nominal
• Stencil 4.21.0 'vanilla' + subpath exports: ❌ failing when importing a subpath, as expected.
• Stencil 4.21.0 'patched' + subpath exports: ✅ compiling, behavior nominal.

To validate, check the linked repo (pay attention to the branch), npm i ; npm start

I'm not necessarily expecting this to be an 'LGTM & merge' but more a base to discuss how to improve Stencil so that it's not a blocker for good practices adoption (pure incompatibility with modern package practice is quite a sore point tbh), which is paramount IMHO for developer-oriented products.