UX: Order categories in edit navigation menu modal by name (#22291)

Why does this change do?

If the `fixed_category_positions` is `false`, we want to order the
categories in the edit navigation menu categories modal by name. This
makes it easier to filter through a large list of categories.

This commit also fixes a bug where we were unintentionally mutating the
`this.site.categories` array.

spec/system/editing_sidebar_categories_navigation_spec.rb

@@ -3,14 +3,6 @@
 RSpec.describe "Editing sidebar categories navigation", type: :system do
   fab!(:user) { Fabricate(:user) }
   fab!(:group) { Fabricate(:group).tap { |g| g.add(user) } }
-  fab!(:category) { Fabricate(:category, name: "category") }
-  fab!(:category_subcategory) do
-    Fabricate(:category, parent_category_id: category.id, name: "category subcategory")
-  end
-
-  fab!(:category_subcategory2) do
-    Fabricate(:category, parent_category_id: category.id, name: "category subcategory 2")
-  end
 
   fab!(:category2) { Fabricate(:category, name: "category2") }
 
@@ -18,6 +10,16 @@ RSpec.describe "Editing sidebar categories navigation", type: :system do
     Fabricate(:category, parent_category_id: category2.id, name: "category2 subcategory")
   end
 
+  fab!(:category) { Fabricate(:category, name: "category") }
+
+  fab!(:category_subcategory2) do
+    Fabricate(:category, parent_category_id: category.id, name: "category subcategory 2")
+  end
+
+  fab!(:category_subcategory) do
+    Fabricate(:category, parent_category_id: category.id, name: "category subcategory")
+  end
+
   let(:sidebar) { PageObjects::Components::Sidebar.new }
 
   before do
@@ -72,6 +74,18 @@ RSpec.describe "Editing sidebar categories navigation", type: :system do
     expect(sidebar).to have_no_section_link(category2.name)
   end
 
+  it "displays the categories in the modal based on the fixed position of the category when `fixed_category_positions` site setting is enabled" do
+    SiteSetting.fixed_category_positions = true
+
+    visit "/latest"
+
+    modal = sidebar.click_edit_categories_button
+
+    expect(modal).to have_categories(
+      [category2, category2_subcategory, category, category_subcategory2, category_subcategory],
+    )
+  end
+
   it "allows a user to deselect all categories in the modal" do
     Fabricate(:category_sidebar_section_link, linkable: category, user: user)
     Fabricate(:category_sidebar_section_link, linkable: category_subcategory2, user: user)

spec/system/page_objects/modals/sidebar_edit_categories.rb

@@ -36,15 +36,15 @@ module PageObjects
       end
 
       def has_categories?(categories)
-        category_ids = categories.map(&:id)
+        category_names = categories.map(&:name)
 
-        has_css?(
-          ".sidebar-categories-form-modal .sidebar-categories-form__category-row",
-          count: category_ids.length,
-        ) &&
-          all(".sidebar-categories-form-modal .sidebar-categories-form__category-row").all? do |row|
-            category_ids.include?(row["data-category-id"].to_i)
-          end
+        categories =
+          all(
+            ".sidebar-categories-form-modal .sidebar-categories-form__category-row",
+            count: category_names.length,
+          )
+
+        expect(categories.map(&:text)).to eq(category_names)
       end
 
       def has_checkbox?(category, disabled: false)