hasStorageAccess() deals with promises in parallel

[domfarolino]

While in parallel, the hasStorageAccess() algorithm creates a promise and fulfills it in-parallel, which is an invalid usage of the Promise API.

More generally, I don't really understand the flow of that algorithm. The method itself returns a promise and then right when it goes in parallel it creates another promise which becomes the resolved value of the outer promise? It seems like we should just pass in the first promise (that was properly created on the main thread) into the https://privacycg.github.io/storage-access/#determine-the-storage-access-policy algorithm, which would then resolve/reject it accordingly.

[cfredric]

Worth noting that both of those issues will be fixed in my PR (#141).

[annevk]

This has indeed been resolved, although we might move back to using in parallel in #174 (but without this issue).