Drop ResourceLoaderTemplateModule and mw.mantle.template

* Nothing is using it any more.
* Drop dependency on ext.mantle.templates
* Remove ResourceLoaderTemplateModule
* Remove mw.mantle.template interface

Dependency: I2c2db7fe162d001b223ac10f9ed493669abb81d7
Change-Id: I69f993f7ca0a98acb592499a002d4f678c4ff0f9