fix: remaining bugs for MPR and toolbar icon colors (#3026)

* feat: warn for overlapping segments

* fix: typo

* refactor mpr toggle and stack sync

* fix: wip for more general mpr

* fix: tool groups for mpr

* fix: changing of viewport id

* fix: viewport Id for the seg viewports

* fix

* update cornerstone version

platform/viewer/public/config/default.js

@@ -4,7 +4,7 @@ window.config = {
   extensions: [],
   modes: [],
   showStudyList: true,
-  // maxNumberOfWebWorkers: 3,
+  maxNumberOfWebWorkers: 4,
   // below flag is for performance reasons, but it might not work for all servers
   omitQuotationForMultipartRequest: true,
   showLoadingIndicator: true,