Additional commands that the client will need
Can be updated during application run for a version change.
||If cached locally and version number matches, won't hit network
||manifest path. Not necessarily from baseUrl
||prepended to all bundle requests. Ends with slash. Typically BundleManager.GetUrlPath(absolutePath).
Implemented in UnityManifestBundleDirectory, and PackedManifest.Loader.
Only valid after Initialize completes without error.