Remove Piwik support (#8835)

* Remove all mentions of Piwik

* Kill off all consumer of the old Piwik Analytics module

* Simplify ModalManager interface

* i18n

* Attempt to fix old e2e tests

* Remove unused component

* Iterate PR

src/group_helpers.tsx

@@ -23,7 +23,7 @@ import SdkConfig, { DEFAULTS } from "./SdkConfig";
 
 export function showGroupReplacedWithSpacesDialog(groupId: string) {
     const learnMoreUrl = SdkConfig.get().spaces_learn_more_url ?? DEFAULTS.spaces_learn_more_url;
-    Modal.createTrackedDialog("Groups are now Spaces", '', QuestionDialog, {
+    Modal.createDialog(QuestionDialog, {
         title: _t("That link is no longer supported"),
         description: <>
             <p>