Glob Entrypoints do not call onResolve

[maths22]

When using a glob entrypoint through the javascript entrypoint, onResolve is not called in plugins on the resulting entrypoints. This breaks e.g. the sentry esbuild plugin which relies on onResolve being called before onLoad. Maybe this is expected behavior, but if it is it should probably be documented clearly.

[jed]

This also causes problems for WASM-based (ie, browser) implementations that use plugins to provide a filesystem. I realize this is tricky, but perhaps onLoad could return a set directory format in JSON (ie [{"name": "foo.txt", "type": "file"}, ...]) for paths ending in trailing slashes? ie, somehow let plugins return directory listings.