Refactor codebase resolving warnings and remove self-package imports

lib/view/pages/more/message/messageView.dart

@@ -0,0 +1,63 @@
+import 'package:flutter/material.dart';
+import 'package:syncfusion_flutter_pdfviewer/pdfviewer.dart';
+import 'package:url_launcher/url_launcher.dart';
+
+import '../../../../api/mhsl/message/getMessages/getMessagesResponse.dart';
+
+class MessageView extends StatefulWidget {
+  final String basePath;
+  final GetMessagesResponseObject message;
+  const MessageView({Key? key, required this.basePath, required this.message}) : super(key: key);
+
+  @override
+  State<MessageView> createState() => _MessageViewState();
+}
+
+class _MessageViewState extends State<MessageView> {
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      appBar: AppBar(
+        title: Text(widget.message.name),
+      ),
+      body: SfPdfViewer.network(
+        widget.basePath + widget.message.url,
+        enableHyperlinkNavigation: true,
+        onDocumentLoadFailed: (PdfDocumentLoadFailedDetails e) {
+          Navigator.of(context).pop();
+          showDialog(context: context, builder: (context) {
+            return AlertDialog(
+              title: const Text("Fehler beim öffnen"),
+              content: Text("Dokument '${widget.message.name}' konnte nicht geladen werden:\n${e.description}"),
+              actions: [
+                TextButton(onPressed: () {
+                  Navigator.of(context).pop();
+                }, child: const Text("Ok"))
+              ],
+            );
+          });
+        },
+        onHyperlinkClicked: (PdfHyperlinkClickedDetails e) {
+          showDialog(
+            context: context,
+            builder: (context) {
+              return AlertDialog(
+                title: const Text("Link öffnen"),
+                content: Text("Möchtest du den folgenden Link öffnen?\n${e.uri}"),
+                actions: [
+                  TextButton(onPressed: () {
+                    Navigator.of(context).pop();
+                  }, child: const Text("Abbrechen")),
+                  TextButton(onPressed: () {
+                    launchUrl(Uri.parse(e.uri), mode: LaunchMode.externalApplication);
+                  }, child: const Text("Öffnen")),
+                ],
+              );
+            },
+          );
+        },
+      ),
+    );
+  }
+}