Feat: Add Create Bottom Sheet and icons

- Implemented a new `CreateBottomSheet` Composable to provide users with options to create AI, Group Chat, or Moment.
- Added new drawable resources for the create options: `ic_create_ai.xml`, `ic_create_group_chat.xml`, `ic_create_monent.xml`, and `ic_create_close.xml`.
- Integrated the `CreateBottomSheet` into the `IndexScreen`. Clicking the "+" button now opens this bottom sheet instead of directly navigating to new post creation.
- Updated `IndexViewModel` to manage the visibility state of the `CreateBottomSheet`.
- Added string resources for the Create Bottom Sheet in English, Chinese, and Japanese.
- Ensured proper navigation and tourist mode checks for each create option.
- Implemented graceful dismissal of the bottom sheet with animations.

app/src/main/res/values-zh/strings.xml

@@ -190,5 +190,12 @@
     <string name="agent_createing">创建中...</string>
     <string name="agent_find">发现</string>
     <string name="text_error_password_too_long">密码不能超过 %1$d 个字符</string>
+    
+    <!-- Create Bottom Sheet -->
+    <string name="create_title">创建</string>
+    <string name="create_ai">AI</string>
+    <string name="create_group_chat_option">群聊</string>
+    <string name="create_moment">动态</string>
+    <string name="create_close">关闭</string>
 
 </resources>