fix: Fix sizes and colors

lib/src/giphy_attachment.dart

@@ -102,7 +102,7 @@ class GiphyAttachment extends StatelessWidget {
                         Icon(
                           StreamIcons.lightning,
                           color: StreamChatTheme.of(context).accentColor,
-                          size: 15.0,
+                          size: 16.0,
                         ),
                         Text(
                           'GIPHY',
@@ -142,6 +142,7 @@ class GiphyAttachment extends StatelessWidget {
                       shape: CircleBorder(),
                     ),
                     Expanded(
+                      child: Center(
                         child: Text(
                           '"${attachment.title}"',
                           style: TextStyle(
@@ -149,6 +150,7 @@ class GiphyAttachment extends StatelessWidget {
                           ),
                         ),
                       ),
+                    ),
                     Card(
                       child: IconButton(
                         icon: Icon(
@@ -191,6 +193,7 @@ class GiphyAttachment extends StatelessWidget {
                       'Cancel',
                       style: TextStyle(
                         fontWeight: FontWeight.bold,
+                        color: Colors.black.withOpacity(0.5)
                       ),
                     ),
                   ],