egui_web: Implement copy, cut and paste

egui_web/Cargo.toml

@@ -22,12 +22,16 @@ parking_lot = "0.11"
 serde = "1"
 serde_json = "1"
 wasm-bindgen = "0.2"
+wasm-bindgen-futures = "0.4"
 
 [dependencies.web-sys]
 version = "0.3"
 features = [
+  'Clipboard',
+  'ClipboardEvent',
   'console',
   'CssStyleDeclaration',
+  'DataTransfer',
   'Document',
   'DomRect',
   'Element',
@@ -36,6 +40,7 @@ features = [
   'KeyboardEvent',
   'Location',
   'MouseEvent',
+  'Navigator',
   'Performance',
   'Storage',
   'Touch',