Split out settings view and made functional

- Split settings out to new views using a core shared layout.
- Extracted added language text to translation files.
- Updated settings routes to be dynamic to category.
- Added redirect for old primary settings route.
- Updated existing tests to cover settings route changes.
- Added tests to cover settings view.
- Improved contrast of settings links for dark mode.

tests/Settings/SettingsTest.php

@@ -0,0 +1,31 @@
+<?php
+
+namespace Tests\Settings;
+
+use Tests\TestCase;
+
+class SettingsTest extends TestCase
+{
+    public function test_settings_endpoint_redirects_to_settings_view()
+    {
+        $resp = $this->asAdmin()->get('/settings');
+
+        $resp->assertRedirect('/settings/features');
+    }
+
+    public function test_settings_category_links_work_as_expected()
+    {
+        $this->asAdmin();
+        $categories = [
+            'features' => 'Features & Security',
+            'customization' => 'Customization',
+            'registration' => 'Registration',
+        ];
+
+        foreach ($categories as $category => $title) {
+            $resp = $this->get("/settings/{$category}");
+            $resp->assertElementContains('h1', $title);
+            $resp->assertElementExists("form[action$=\"/settings/{$category}\"]");
+        }
+    }
+}