add an optional cache and exclude option to the onResolve plugin hook

[sod]

As the angular-cli right now fully commits to esbuild, the onResolve hook reveals itself as a pretty stark performance hinderance to the otherwise astonishing speed of esbuild.

In my mind this is how the API could look like to improve:

build.onResolve({ filter: /^[^./]/, exclude: /^(@angular|rxjs)\// } }, async (args) => {
    if (/* some condition */) {
        return { path: args.path, external: true, cachable: true };
    }

    return { path: args.path, cachable: true };
});

1. The exclude option could be a way around the missing lookahead feature of go-regex. To stamp out imports we don't want to look at
2. The opt-in cachable: true could tell esbuild to not ask for the same information again, which would be nice for watcher performance

Would you be open to this idea and if yes, would you appreciate a PR contribution?

[sod]

Maybe the cachable is a bit much. But the exclude option could go a long way.