Add Azure Blob Storage archive & email safety net

- Add AzureBlobStorageService, DocumentArchiveSyncService, and related config for secondary PDF archiving of invoices/reminders
- Add SQL procs and schema changes for archive backfill
- Update invoice/reminder services to upload PDFs to blob storage
- Add telemetry counters and unit tests for blob storage/archive logic
- Add Fuchs:Email:OverrideRecipient config and enforce dev/test email redirect in ProcessWebComService, with tests
- Improve JS date parsing (German formats), stricter JSON date detection
- Increase widget SQL timeouts, update dependencies, docs, and project files

Fuchs/js/intranet/oci_main.js

@@ -11,9 +11,13 @@
         $(this).remove();
         api.rendered = false;
     };
-    $ocms.isDateString = function (inp) {
+    /* Tests whether a string is a JSON/ISO-8601 date(-time) value as emitted by the
+       backend's JSON serializer (e.g. Newtonsoft "2021-09-09T00:00:00[.fff][Z|+hh:mm]").
+       Deliberately NOT based on the native Date constructor, which guesses ambiguous
+       formats (e.g. dotted dd.MM.yy strings) heuristically and inconsistently. */
+    $ocms.isJSONDateString = function (inp) {
         if (typeof inp !== 'string') { return false; } else {
-            return isNaN(new Date(inp)) === false;
+            return /^\d{4}-\d{2}-\d{2}(T\d{2}:\d{2}:\d{2}(\.\d+)?(Z|[+-]\d{2}:\d{2})?)?$/.test(inp);
         }
     }
     $ocms.failure = function (jqXHR) {