feat: added themes

lib/src/option_list_tile.dart

@@ -1,4 +1,5 @@
 import 'package:flutter/material.dart';
+import 'package:stream_chat_flutter/src/stream_chat_theme.dart';
 import 'package:stream_chat_flutter/src/stream_svg_icon.dart';
 
 class OptionListTile extends StatelessWidget {
@@ -21,13 +22,13 @@ class OptionListTile extends StatelessWidget {
     return Column(
       children: [
         Container(
-          color: Color(0xffe6e6e6),
-          height: 2.0,
+          color: StreamChatTheme.of(context).colorTheme.greyGainsboro,
+          height: 1.0,
         ),
         Material(
-          color: Colors.white,
+          color: StreamChatTheme.of(context).colorTheme.white,
           child: Container(
-            height: 56.0,
+            height: 63.0,
             child: InkWell(
               onTap: onTap,
               child: Row(
@@ -44,10 +45,14 @@ class OptionListTile extends StatelessWidget {
                     flex: 4,
                     child: Text(
                       title,
-                      style: TextStyle(
-                        fontWeight: FontWeight.bold,
-                        color: titleColor,
-                      ),
+                      style: titleColor == null
+                          ? StreamChatTheme.of(context).textTheme.bodyBold
+                          : StreamChatTheme.of(context)
+                              .textTheme
+                              .bodyBold
+                              .copyWith(
+                                color: titleColor,
+                              ),
                     ),
                   ),
                   Expanded(