[2.x] Allow custom classes on the dropdown class (#661)

* Allow custom classes on the dropdown class

Use case: a person may want to show the dropdown on the left on mobile, but to the right on the web. Currently they don't have an option for that. So they could do:

`left-0 md:right-0`

* Update dropdown.blade.php

* Update dropdown.blade.php

* Update dropdown.blade.php

* Update dropdown.blade.php

* Update dropdown.blade.php

Co-authored-by: Taylor Otwell <taylor@laravel.com>

resources/views/components/dropdown.blade.php

@@ -1,4 +1,4 @@
-@props(['align' => 'right', 'width' => '48', 'contentClasses' => 'py-1 bg-white'])
+@props(['align' => 'right', 'width' => '48', 'contentClasses' => 'py-1 bg-white', 'dropdownClasses' => ''])
 
 @php
 switch ($align) {
@@ -8,6 +8,10 @@
     case 'top':
         $alignmentClasses = 'origin-top';
         break;
+    case 'none':
+    case 'false':
+        $alignmentClasses = '';
+        break;
     case 'right':
     default:
         $alignmentClasses = 'origin-top-right right-0';
@@ -33,7 +37,7 @@
             x-transition:leave="transition ease-in duration-75"
             x-transition:leave-start="transform opacity-100 scale-100"
             x-transition:leave-end="transform opacity-0 scale-95"
-            class="absolute z-50 mt-2 {{ $width }} rounded-md shadow-lg {{ $alignmentClasses }}"
+            class="absolute z-50 mt-2 {{ $width }} rounded-md shadow-lg {{ $alignmentClasses }} {{ $dropdownClasses }}"
             style="display: none;"
             @click="open = false">
         <div class="rounded-md ring-1 ring-black ring-opacity-5 {{ $contentClasses }}">