Returns a URI that allows a file to be loaded given a plugin package and a path relative to the plugin's package path
the package this the file is contained in
OptionalpkgRelativePath: stringthe path of the file relative to the package path, e.g. 'resources/snippets.json'
Creates URIs for resources used in plugin contributions. Projects where plugin host is not located on the back-end machine and therefor resources cannot be loaded from the local file system in the back end can override the factory.