FEATURE: Poll breakdown 2.0 (#10345)

The poll breakdown modal replaces the grouped pie charts feature.

Includes:

* MODAL: Untangle `onSelectPanel`
Previously modal-tab component would call on click the onSelectPanel callback with itself (modal-tab) as `this` which severely limited its usefulness. Now showModal binds the callback to its controller.

"The PR includes a fix/change to d-modal (b7f6ec6) that hasn't been extracted to a separate PR because it's not currently possible to test a change like this in abstract, i.e. with dynamically created controllers/components in tests. The percentage/count toggle test for the poll breakdown feature is essentially a test for that d-modal modification."

plugins/poll/assets/javascripts/initializers/add-poll-ui-builder.js.es6

@@ -1,6 +1,6 @@
 import { withPluginApi } from "discourse/lib/plugin-api";
-import discourseComputed from "discourse-common/utils/decorators";
 import showModal from "discourse/lib/show-modal";
+import discourseComputed from "discourse-common/utils/decorators";
 
 function initializePollUIBuilder(api) {
   api.modifyClass("controller:composer", {

plugins/poll/assets/javascripts/initializers/extend-for-poll.js.es6

@@ -1,8 +1,8 @@
 import EmberObject from "@ember/object";
 import { withPluginApi } from "discourse/lib/plugin-api";
-import { observes } from "discourse-common/utils/decorators";
-import { getRegister } from "discourse-common/lib/get-owner";
 import WidgetGlue from "discourse/widgets/glue";
+import { getRegister } from "discourse-common/lib/get-owner";
+import { observes } from "discourse-common/utils/decorators";
 
 function initializePolls(api) {
   const register = getRegister(api);