error handler improved, fixes

packages/web/src/utility/ErrorHandler.svelte

@@ -0,0 +1,46 @@
+<script lang="ts">
+  import localforage from 'localforage';
+
+  let counter = 0;
+  $: counterCopy = counter;
+
+  const onunhandledrejection = async e => {
+    console.log('Unhandler error, checking whether crashed', e);
+    const oldCounter = counter;
+    counter++;
+    window.setTimeout(async () => {
+      if (counterCopy <= oldCounter) {
+        console.log('CRASH DETECTED!!!');
+        const lastDbGateCrashJson = localStorage.getItem('lastDbGateCrash');
+        const lastDbGateCrash = lastDbGateCrashJson ? JSON.parse(lastDbGateCrashJson) : null;
+
+        if (lastDbGateCrash && new Date().getTime() - lastDbGateCrash < 30 * 1000) {
+          if (
+            window.confirm(
+              'Sorry, DbGate has crashed again.\nDo you want to clear local user data to avoid crashing after next reload?'
+            )
+          ) {
+            localStorage.clear();
+            try {
+              await localforage.clear();
+            } catch (err) {
+              console.error('Error clearing app data', err);
+            }
+            window.location.reload();
+          }
+        } else {
+          if (
+            window.confirm(
+              'Sorry, DbGate has crashed.\nPress OK for reload application\nPress Cancel and inspect Console in Developer tools for error details'
+            )
+          ) {
+            localStorage.setItem('lastDbGateCrash', JSON.stringify(new Date().getTime()));
+            window.location.reload();
+          }
+        }
+      }
+    }, 500);
+  };
+</script>
+
+<svelte:window on:unhandledrejection={onunhandledrejection} />