Initial commit for Query Store extension (#23260)

* Initial commit for Query Store extension

* fix eslint explicit-functino-return-type setting

* address comments

* remove specifying explicit-function-return-type eslint rule

* update strings

extensions/query-store/tsconfig.json

@@ -0,0 +1,15 @@
+{
+	"extends": "../tsconfig.base.json",
+	"compileOnSave": true,
+	"compilerOptions": {
+		"outDir": "./out",
+		"lib": [
+			"es6",
+			"es2015.promise",
+			"dom"
+		]
+	},
+	"exclude": [
+		"node_modules"
+	]
+}