Seperate module source provider for library and plugin code.

Currently, both library and plugin uses UrlModuleSourceProvider. But assets are packaged to jar on deployment and UrlModuleSourceProvider cannot read source from jar. So this patch makes Beyond uses AssetsModuleSourceProvider for library.
But plugin code still should read with UrlModuleSourceProvider.

To implement it this patch makes BeyondGlobal takes ModuleSourceProvider as an argument. This provider will be used for library code.