feat: Merge Data Source (#3788)

Add the ability to merge two different series queries to generate a complete study query result.  Provides basic support for other types of merges, but those aren't yet added as full features.

platform/core/src/extensions/ExtensionManager.ts

@@ -464,7 +464,8 @@ export default class ExtensionManager extends PubSubService {
     const { userAuthenticationService } = this._servicesManager.services;
     const dataSourceInstance = module.createDataSource(
       dataSourceDef.configuration,
-      userAuthenticationService
+      userAuthenticationService,
+      this
     );
 
     this.dataSourceMap[dataSourceDef.sourceName] = [dataSourceInstance];