Add datavirtualization extension (#21594)

* initial

* cleanup

* Add typings ref

* fix compile

* remove unused

* add missing

* another unused

* Use newer vscodetestcover

* newer dataprotocol

* format

* cleanup ignores

* fix out path

* fix entry point

* more cleanup

* Move into src folder

* Handle service client log messages

* remove unused

extensions/datavirtualization/tslint.json

@@ -0,0 +1,14 @@
+{
+	"linterOptions": {
+		"exclude": [
+			"typings/*.d.ts"
+		]
+	},
+	"rules": {
+		"no-unused-expression": false,
+		"curly": true,
+		"class-name": true,
+		"semicolon": true,
+		"triple-equals": true
+	}
+}