Write an APK parser that extracts the APK's bundleId and supported architectures

[hackergrrl]

Split off from #585, which depends on this.

There is an Android Java API to read this data, and that API can be called from React Native e.g. see https://github.com/staltz/dat-installer/blob/master/android/app/src/main/java/com/staltz/datinstaller/PackageInfoModule.java

However, this information is needed by the backend nodejs process, so accessing it via the Android Java API would require a complex back-and-forth via the React Native process.

It would be better to read this information directly from the APK in the nodejs-mobile process. An APK is a Zip archive, and the version and bundleId are stored in the file AndroidManifest.xml that is always present in the root of the Zip archive (see https://developer.android.com/guide/topics/manifest/manifest-intro). AndroidManifest.xml is encoded as binary XML.

Fortunately there is a tool to read this information: app-info-parser. This tool also reads the resources.arsc file, which includes the app icons, which we don't need to it adds a small memory overhead, but if this is a performance issue in the future we could fork app-info-parser and make that parsing separate.

Note that the package field of the APK almost always, but not actually always, the same as the applicationId see https://developer.android.com/guide/topics/manifest/manifest-element#package I think in our case we can trust that it is the same, but I don't quite understand this difference.

Unfortunately there is no Java API for reading the supported architectures within an APK (at least I can't find one). I think the best way to read the supported architectures of an APK would be to read the contents of the lib folder in the APK. It will contain a folder for each supported architecture. I have started work to add a readdir() method to random-access-zip (also, the name is bad, it should be zip-fs since it replicates the fs methods for a zipfile).