feat: Implement media picker and camera functionality

- Added permissions for CAMERA, READ_EXTERNAL_STORAGE, READ_MEDIA_IMAGES, and READ_MEDIA_VIDEO in AndroidManifest.xml.
- Introduced MediaPickerBottomSheet for selecting images and videos from the gallery.
- Implemented camera functionality to capture images and send them in chat.
- Created MediaUtils for handling image and file conversions to Base64.
- Updated ChatDetailScreen to handle media selection and sending images/files.
- Enhanced ChatViewModel with methods to send image and file messages.
- Added file_paths.xml for FileProvider configuration.

app/src/main/res/xml/file_paths.xml

@@ -0,0 +1,14 @@
+<?xml version="1.0" encoding="utf-8"?>
+<paths xmlns:android="http://schemas.android.com/apk/res/android">
+    <!-- Cache directory for camera photos -->
+    <cache-path name="cache" path="." />
+    
+    <!-- External cache directory -->
+    <external-cache-path name="external_cache" path="." />
+    
+    <!-- Files directory -->
+    <files-path name="files" path="." />
+    
+    <!-- External files directory -->
+    <external-files-path name="external_files" path="." />
+</paths>