[MM-47970] + [MM-47754] Downloads fixes (#2326)

* Use downloads location as default when clicking "Save as". Remove update from downloads after upgrade when application starts

* Fix issue where "addedAt" was extracted from undefined object

* Fix tests

src/renderer/components/DownloadsDropdown/FileSizeAndStatus.tsx

@@ -15,7 +15,7 @@ type OwnProps = {
 const FileSizeAndStatus = ({item}: OwnProps) => {
     const translate = useIntl();
 
-    const {totalBytes, receivedBytes, addedAt} = item;
+    const {totalBytes, receivedBytes, addedAt} = item || {};
 
     const getRemainingTime = useCallback(() => {
         const elapsedMs = Date.now() - addedAt;