TW-731: rebuild copy/paste text

assets/l10n/intl_en.arb

@@ -2760,5 +2760,9 @@
     "thisMessageHasBeenEncrypted": "This message has been encrypted",
     "roomCreationFailed": "Room creation failed",
     "errorGettingPdf": "Error getting PDF",
-    "errorPreviewingFile": "Error previewing file"
+    "errorPreviewingFile": "Error previewing file",
+    "paste": "Paste",
+    "cut": "Cut",
+    "pasteImageFailed": "Paste image failed",
+    "copyImageFailed": "Copy image failed"
 }

lib/presentation/enum/chat/popup_menu_item_web_enum.dart

@@ -0,0 +1,5 @@
+enum InputBarContextMenu {
+  copy,
+  cut,
+  paste,
+}

lib/presentation/extensions/text_editting_controller_extension.dart

@@ -0,0 +1,40 @@
+import 'package:fluffychat/utils/clipboard.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter/services.dart' as flutter;
+
+extension TextEdittingControllerExtension on TextEditingController {
+  Future<void> pasteText() async {
+    final start = selection.start;
+    final end = selection.end;
+    final pastedText = await Clipboard.instance.pasteText();
+    if (pastedText != null) {
+      if (start == -1 || end == -1) {
+        text = pastedText + text;
+        return;
+      }
+      if (start == end) {
+        final startText = text.substring(0, start);
+        final trailingText = text.substring(end, text.length);
+        text = startText + pastedText + trailingText;
+      } else {
+        text = text.replaceRange(start, end, pastedText);
+      }
+    }
+  }
+
+  Future<void> copyText() async {
+    final start = selection.start;
+    final end = selection.end;
+    if (start < end) {
+      await flutter.Clipboard.setData(
+        flutter.ClipboardData(
+          text: text.substring(start, end),
+        ),
+      );
+    }
+  }
+
+  Future<void> cutText() async {
+    //TO-DO:
+  }
+}