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.

extensions/default/jest.config.js

@@ -0,0 +1,17 @@
+const base = require('../../jest.config.base.js');
+const pkg = require('./package');
+
+module.exports = {
+  ...base,
+  name: pkg.name,
+  displayName: pkg.name,
+  moduleNameMapper: {
+    ...base.moduleNameMapper,
+    '@ohif/(.*)': '<rootDir>/../../platform/$1/src',
+  },
+  // rootDir: "../.."
+  // testMatch: [
+  //   //`<rootDir>/platform/${pack.name}/**/*.spec.js`
+  //   "<rootDir>/platform/app/**/*.test.js"
+  // ]
+};