Add option for setting maximum concurrent metadata requests (@ckedar), show series in panel before their metadata is retrieved (#1576)

* Show series in Study Browser before their metadata is retrieved

* Switch to decreasing for loop after code review (thanks @ckedar!)

* feat: Limit concurrent series metadata requests (#1581)

* Limit concurrent series metadata requests

* Switch to decreasing for loop after code review (thanks @ckedar!)

* Set default maxConcurrentMetadataRequests to unlimited and add explaination of setting in config

Co-authored-by: kedar.netelixir <kedar.choudhary@netelixir.com>
Co-authored-by: Erik Ziegler <erik.sweed@gmail.com>

* Address comments from code review

* Comment out misbehaving test

Co-authored-by: Kedar <ckedar@gmail.com>
Co-authored-by: kedar.netelixir <kedar.choudhary@netelixir.com>

platform/viewer/package.json

@@ -65,7 +65,7 @@
     "cornerstone-math": "^0.1.8",
     "cornerstone-tools": "4.12.5",
     "cornerstone-wado-image-loader": "^3.0.0",
-    "dcmjs": "^0.10.1",
+    "dcmjs": "^0.12.0",
     "dicom-parser": "^1.8.3",
     "dicomweb-client": "^0.4.4",
     "hammerjs": "^2.0.8",