Add the functionality to import a curl file into the app.

The user can click on the button saying "+ Import" after which, they
will be allow to drop a curl file and import the curl command in the
app.

lib/widgets/drag_and_drop_area.dart

@@ -0,0 +1,51 @@
+import 'package:desktop_drop/desktop_drop.dart';
+import 'package:file_selector/file_selector.dart';
+import 'package:flutter/material.dart';
+
+class DragAndDropArea extends StatefulWidget {
+  final Function(XFile) onFileDropped;
+
+  const DragAndDropArea({super.key, required this.onFileDropped});
+
+  @override
+  State<DragAndDropArea> createState() => _DragAndDropAreaState();
+}
+
+class _DragAndDropAreaState extends State<DragAndDropArea> {
+  final List<XFile> _list = [];
+  bool _dragging = false;
+
+  @override
+  Widget build(BuildContext context) {
+    return DropTarget(
+      onDragDone: (detail) {
+        setState(() {
+          _list.addAll(detail.files);
+        });
+        widget.onFileDropped(detail.files[0]);
+      },
+      onDragEntered: (detail) {
+        setState(() {
+          _dragging = true;
+        });
+      },
+      onDragExited: (detail) {
+        setState(() {
+          _dragging = false;
+        });
+      },
+      child: Container(
+        decoration: BoxDecoration(
+          borderRadius: BorderRadius.circular(22),
+          color: _dragging ? Colors.blue.withOpacity(0.4) : Colors.black26,
+          border: Border.all(color: Colors.white24),
+        ),
+        width: 600,
+        height: 400,
+        child: _list.isEmpty
+            ? const Center(child: Text("Drop here"))
+            : Text(_list.map((e) => e.path).join("\n")),
+      ),
+    );
+  }
+}