Added raw-failure logs to flutter app (to debug init errors)

flutter/lib/pages/debug/debug_persistence_failurelogfile.dart

@@ -0,0 +1,64 @@
+import 'dart:io';
+
+import 'package:flutter/material.dart';
+import 'package:shared_preferences/shared_preferences.dart';
+import 'package:simplecloudnotifier/components/layout/scaffold.dart';
+import 'package:simplecloudnotifier/types/immediate_future.dart';
+
+class DebugFailureLogFilePage extends StatefulWidget {
+  final String path;
+
+  DebugFailureLogFilePage({required this.path}) {}
+
+  @override
+  State<DebugFailureLogFilePage> createState() => _DebugFailureLogFilePageState();
+}
+
+class _DebugFailureLogFilePageState extends State<DebugFailureLogFilePage> {
+  ImmediateFuture<String>? _futureContent;
+
+  @override
+  void initState() {
+    super.initState();
+
+    _futureContent = ImmediateFuture.ofFuture(new File(this.widget.path).readAsString());
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return SCNScaffold(
+      title: 'FailureLog',
+      showSearch: false,
+      child: () {
+        if (_futureContent == null) {
+          return Center(child: CircularProgressIndicator());
+        }
+
+        return FutureBuilder(
+          future: _futureContent!.future,
+          builder: ((context, snapshot) {
+            if (_futureContent?.value != null) {
+              return _buildContent(context, _futureContent!.value!);
+            } else if (snapshot.connectionState == ConnectionState.done && snapshot.hasError) {
+              return Text('Error: ${snapshot.error}'); //TODO better error display
+            } else if (snapshot.connectionState == ConnectionState.done) {
+              return _buildContent(context, snapshot.data!);
+            } else {
+              return Center(child: CircularProgressIndicator());
+            }
+          }),
+        );
+      }(),
+    );
+  }
+
+  Widget _buildContent(BuildContext context, String value) {
+    return SingleChildScrollView(
+      scrollDirection: Axis.horizontal,
+      child: Padding(
+        padding: const EdgeInsets.all(8.0),
+        child: Text(value, style: TextStyle(fontFamily: "monospace")),
+      ),
+    );
+  }
+}