new: add `duplicate` button for articles

resources/views/components/form/button.blade.php

@@ -15,7 +15,20 @@
     @isset($trigger) data-trigger="{{ $trigger }}" @endisset
     @isset($container) data-container="{{ $container }}" @endisset
     @isset($html) data-html="true" @endisset
-    @isset($metadata) {{ $metadata }} @endisset>
+    @isset($metadata) {{ $metadata }} @endisset
+    @isset($attr)
+        @if (is_array($attr))
+            @foreach ($attr as $key => $value)
+                @if ($value === true)
+                    {{ $key }}
+                @elseif ($value !== false && $value !== null)
+                    {{ $key }}="{{ $value }}"
+                @endif
+            @endforeach
+        @else
+            {{ $attr }}
+        @endif
+    @endisset>
     <i class="fa fa-fw {{ $icon ?? '' }}"></i>
     {{ $txt ?? '' }}
 </button>