use dojo/query not dojo/_base/query, refs #16585
When possible without breaking backwards compatibility, use dojo/Deferred instead of dojo/_base/Deferred.    I could actually change the other dojo/_base/Deferred usages too if I used a shim like dijit/Tree does, but it didn't seem worth it.  Refs #16585 !strict
_earlyTemplatedStartup is for _WidgetsInTemplateMixin; no reason to (also) declare it in _TemplatedMixin, refs #12275 !strict