DEV: makes chat modals use the new <DModal /> component (#22495)

This commit also standardize the naming pattern of modals: `<Chat::Modal::FooBar />` and changes css class accordingly.

Co-authored-by: David Taylor <david@taylorhq.com>

app/assets/javascripts/discourse/app/components/d-modal-cancel.hbs

@@ -1,5 +1,5 @@
 <DButton
   @class="btn-flat d-modal-cancel"
-  @action={{action this.close}}
+  @action={{@close}}
   @translatedLabel={{i18n "cancel"}}
 />

app/assets/javascripts/discourse/app/components/d-modal-cancel.js

@@ -1,4 +0,0 @@
-import Component from "@ember/component";
-export default Component.extend({
-  tagName: "",
-});

app/assets/javascripts/discourse/tests/integration/components/select-kit/single-select-test.js

@@ -490,4 +490,20 @@ module("Integration | Component | select-kit/single-select", function (hooks) {
 
     assert.dom(".single-select.is-expanded").exists();
   });
+
+  test("options.formName", async function (assert) {
+    setDefaultState(this);
+    await render(hbs`
+      <SingleSelect
+        @value={{this.value}}
+        @content={{this.content}}
+        @options={{hash formName="foo"}}
+      />
+    `);
+
+    assert
+      .dom('input[name="foo"]')
+      .hasAttribute("type", "hidden")
+      .hasAttribute("value", "1");
+  });
 });

app/assets/javascripts/select-kit/addon/components/select-kit.js

@@ -311,6 +311,7 @@ export default Component.extend(
       hiddenValues: null,
       disabled: false,
       expandedOnInsert: false,
+      formName: null,
     },
 
     autoFilterable: computed("content.[]", "selectKit.filter", function () {

app/assets/javascripts/select-kit/addon/components/selected-name.hbs

@@ -6,6 +6,14 @@
     data-name={{this.name}}
     class="select-kit-selected-name selected-name choice"
   >
+    {{#if this.selectKit.options.formName}}
+      <input
+        type="hidden"
+        name={{this.selectKit.options.formName}}
+        value={{this.value}}
+      />
+    {{/if}}
+
     {{#if this.item.icon}}
       {{d-icon this.item.icon}}
     {{/if}}