DEV: Remove usage of {{action}} modifiers - Take 2 (#18476)

This PR enables the [`no-action-modifiers`](https://github.com/ember-template-lint/ember-template-lint/blob/master/docs/rule/no-action-modifiers.md) template lint rule and removes all usages of the `{{action}}` modifier in core.

In general, instances of `{{action "x"}}` have been replaced with `{{on "click" (action "x")}}`. 

In many cases, such as for `a` elements, we also need to prevent default event handling to avoid unwanted side effects. While the `{{action}}` modifier internally calls `event.preventDefault()`, we need to handle these cases more explicitly. For this purpose, this PR also adds the [ember-event-helpers](https://github.com/buschtoens/ember-event-helpers) dependency so we can use the `prevent-default` handler. For instance:

```
<a href {{on "click" (prevent-default (action "x"))}}>Do X</a>
```

Note that `action` has not in general been refactored away as a helper yet. In general, all event handlers should be methods on the corresponding component and referenced directly (e.g. `{{on "click" this.doSomething}}`). However, the `action` helper is used extensively throughout the codebase and often references methods in the `actions` hash on controllers or routes. Thus this refactor will also be extensive and probably deserves a separate PR.

Note: This work was done to complement #17767 by minimizing the potential impact of the `action` modifier override, which uses private API and arguably should be replaced with an AST transform.

This is a followup to #18333, which had to be reverted because it did not account for the default treatment of modifier keys by the {{action}} modifier.

Commits:
* Enable `no-action-modifiers` template lint rule
* Replace {{action "x"}} with {{on "click" (action "x")}}
* Remove unnecessary action helper usage
* Remove ctl+click tests for user-menu
   These tests now break in Chrome when used with addEventListener. As per the comment, they can probably be safely removed.
* Prevent default event handlers to avoid unwanted side effects
   Uses `event.preventDefault()` in event handlers to prevent default event handling. This had been done automatically by the `action` modifier, but is not always desirable or necessary.
* Restore UserCardContents#showUser action to avoid regression
   By keeping the `showUser` action, we can avoid a breaking change for plugins that rely upon it, while not interfering with the `showUser` argument that's been passed.
* Revert EditCategoryTab#selectTab -> EditCategoryTab#select
   Avoid potential breaking change in themes / plugins
* Restore GroupCardContents#showGroup action to avoid regression
   By keeping the `showGroup` action, we can avoid a breaking change for plugins that rely upon it, while not interfering with the `showGroup` argument that's been passed.
* Restore SecondFactorAddTotp#showSecondFactorKey action to avoid regression
   By keeping the `showSecondFactorKey` action, we can avoid a breaking change for plugins that rely upon it, while not interfering with the `showSecondFactorKey` property that's maintained on the controller.
* Refactor away from `actions` hash in ChooseMessage component
* Modernize EmojiPicker#onCategorySelection usage
* Modernize SearchResultEntry#logClick usage
* Modernize Discovery::Categories#showInserted usage
* Modernize Preferences::Account#resendConfirmationEmail usage
* Modernize MultiSelect::SelectedCategory#onSelectedNameClick usage
* Favor fn over action in SelectedChoice component
* Modernize WizardStep event handlers
* Favor fn over action usage in buttons
* Restore Login#forgotPassword action to avoid possible regression
* Introduce modKeysPressed utility
   Returns an array of modifier keys that are pressed during a given `MouseEvent` or `KeyboardEvent`.
* Don't interfere with click events on links with `href` values when modifier keys are pressed

app/assets/javascripts/admin/addon/components/admin-theme-editor.js

@@ -3,6 +3,7 @@ import I18n from "I18n";
 import discourseComputed from "discourse-common/utils/decorators";
 import { fmt } from "discourse/lib/computed";
 import { isDocumentRTL } from "discourse/lib/text-direction";
+import { action } from "@ember/object";
 import { next } from "@ember/runloop";
 
 export default Component.extend({
@@ -91,15 +92,26 @@ export default Component.extend({
     return this.theme.getError(target, fieldName);
   },
 
+  @action
+  toggleShowAdvanced(event) {
+    event?.preventDefault();
+    this.toggleProperty("showAdvanced");
+  },
+
+  @action
+  toggleAddField(event) {
+    event?.preventDefault();
+    this.toggleProperty("addingField");
+  },
+
+  @action
+  toggleMaximize(event) {
+    event?.preventDefault();
+    this.toggleProperty("maximized");
+    next(() => this.appEvents.trigger("ace:resize"));
+  },
+
   actions: {
-    toggleShowAdvanced() {
-      this.toggleProperty("showAdvanced");
-    },
-
-    toggleAddField() {
-      this.toggleProperty("addingField");
-    },
-
     cancelAddField() {
       this.set("addingField", false);
     },
@@ -114,11 +126,6 @@ export default Component.extend({
       this.fieldAdded(this.currentTargetName, name);
     },
 
-    toggleMaximize() {
-      this.toggleProperty("maximized");
-      next(() => this.appEvents.trigger("ace:resize"));
-    },
-
     onlyOverriddenChanged(value) {
       this.onlyOverriddenChanged(value);
     },