desktop: files Drag & Drop support (#2843)

* desktop: files Drag&Drop support

* reduce diff

* move

* move 2

* move 3

---------

Co-authored-by: Evgeny Poberezkin <2769109+epoberezkin@users.noreply.github.com>

apps/multiplatform/common/src/androidMain/kotlin/chat/simplex/common/platform/Modifier.android.kt

@@ -2,6 +2,7 @@ package chat.simplex.common.platform
 
 import androidx.compose.runtime.Composable
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.painter.Painter
 import com.google.accompanist.insets.navigationBarsWithImePadding
 
 actual fun Modifier.navigationBarsWithImePadding(): Modifier = navigationBarsWithImePadding()
@@ -14,3 +15,11 @@ actual fun ProvideWindowInsets(
 ) {
   com.google.accompanist.insets.ProvideWindowInsets(content = content)
 }
+
+@Composable
+actual fun Modifier.desktopOnExternalDrag(
+  enabled: Boolean,
+  onFiles: (List<String>) -> Unit,
+  onImage: (Painter) -> Unit,
+  onText: (String) -> Unit
+): Modifier = this