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/config/locales/client.en.yml

@@ -52,10 +52,6 @@ en:
         title: "Group votes by user field"
         label: "Show breakdown"
 
-      ungroup-results:
-        title: "Combine all votes"
-        label: "Hide breakdown"
-
       export-results:
         title: "Export the poll results"
         label: "Export"
@@ -74,6 +70,13 @@ en:
         closes_in: "Closes in <strong>%{timeLeft}</strong>."
         age: "Closed <strong>%{age}</strong>"
 
+      breakdown:
+        title: "Poll results"
+        votes: "%{count} votes"
+        breakdown: "Breakdown"
+        percentage: "Percentage"
+        count: "Count"
+
       error_while_toggling_status: "Sorry, there was an error toggling the status of this poll."
       error_while_casting_votes: "Sorry, there was an error casting your votes."
       error_while_fetching_voters: "Sorry, there was an error displaying the voters."