fixed settings overflow

added option to disable snackbar for login
added option to customize theme based on dark mode status

lib/api/client.dart

@@ -19,6 +19,7 @@ class Client {
   String _base = '';
   bool authenticated = false;
   bool ignoreCertificates = false;
+  bool showSnackBar = true;
 
   String get base => _base;
   String get token => _token;
@@ -139,7 +140,7 @@ class Client {
       final SnackBar snackBar = SnackBar(
         content: Text(
             "Error code " + response.statusCode.toString() + " received."),
-        action: SnackBarAction(
+        action: globalNavigatorKey.currentContext == null ? null : SnackBarAction(
           label: ("Details"),
           onPressed: () {
             showDialog(
@@ -160,7 +161,7 @@ class Client {
           },
         ),
       );
-      if(global_scaffold_key != null)
+      if(global_scaffold_key != null && showSnackBar)
         global_scaffold_key!.currentState?.showSnackBar(snackBar);
       else
         print("error on request: ${error["message"]}");

lib/pages/settings.dart

@@ -60,7 +60,7 @@ class SettingsPageState extends State<SettingsPage> {
     return new Scaffold(
       appBar: AppBar(title: Text("Settings"),),
 
-      body: Column(
+      body: ListView(
         children: [
           UserAccountsDrawerHeader(
             accountName: currentUser != null ? Text(currentUser.username) : null,

lib/pages/user/login.dart

@@ -271,6 +271,7 @@ class _LoginPageState extends State<LoginPage> {
     setState(() => _loading = true);
     try {
       var vGlobal = VikunjaGlobal.of(context);
+      vGlobal.client.showSnackBar = false;
       vGlobal.client.configure(base: _server);
       Server? info = await vGlobal.serverService.getInfo();
       if (info == null)
@@ -336,6 +337,7 @@ class _LoginPageState extends State<LoginPage> {
               ));
      */
     } finally {
+      VikunjaGlobal.of(context).client.showSnackBar = true;
       setState(() {
         _loading = false;
       });

lib/theme/theme.dart

@@ -4,9 +4,9 @@ import 'package:flutter/material.dart';
 import 'package:vikunja_app/theme/constants.dart';
 
 ThemeData buildVikunjaTheme() => _buildVikunjaTheme(ThemeData.light());
-ThemeData buildVikunjaDarkTheme() => _buildVikunjaTheme(ThemeData.dark());
+ThemeData buildVikunjaDarkTheme() => _buildVikunjaTheme(ThemeData.dark(), isDark: true);
 
-ThemeData _buildVikunjaTheme(ThemeData base) {
+ThemeData _buildVikunjaTheme(ThemeData base, {bool isDark = false}) {
   return base.copyWith(
     errorColor: vRed,
     primaryColor: vPrimaryDark,