updated chatTextfield.dart design and added file and gallery picker

pubspec.yaml

@@ -64,6 +64,8 @@ dependencies:
       url: https://github.com/Harsh223/flowder.git
   persistent_bottom_nav_bar: ^5.0.2
   badges: ^3.0.2
+  image_picker: ^0.8.7+4
+  file_picker: ^5.2.11
 
 dependency_overrides:
   xml: ^6.2.2