feat: Added giphy for giphyEnabled mode

lib/src/message_input.dart

@@ -291,7 +291,9 @@ class MessageInputState extends State<MessageInput> {
               ),
               contentPadding: EdgeInsets.all(4),
               prefixIcon: _giphyEnabled
-                  ? Chip(
+                  ? Padding(
+                    padding: const EdgeInsets.symmetric(horizontal: 2.0),
+                    child: Chip(
                         backgroundColor: StreamChatTheme.of(context).accentColor,
                         label: Text(
                           'GIPHY',
@@ -301,6 +303,7 @@ class MessageInputState extends State<MessageInput> {
                           StreamIcons.lightning,
                           color: Colors.white,
                         ),
+                      ),
                   )
                   : null,
               suffixIcon: _giphyEnabled
@@ -932,11 +935,15 @@ class MessageInputState extends State<MessageInput> {
 
   /// Sends the current message
   void sendMessage() async {
-    final text = textEditingController.text.trim();
+    var text = textEditingController.text.trim();
     if (text.isEmpty && _attachments.isEmpty) {
       return;
     }
 
+    if(_giphyEnabled) {
+      text = '/giphy' + text;
+    }
+
     final attachments = List<_SendingAttachment>.from(_attachments);
 
     textEditingController.clear();