License extension (#1174)

* License menu item should come from an extension #1141

Signed-off-by: Roman <ixrock@gmail.com>

* fix: expose `Util.openExternal` via extensions-api

Signed-off-by: Roman <ixrock@gmail.com>

* move LICENSE back to root

Signed-off-by: Roman <ixrock@gmail.com>

extensions/license-menu-item/tsconfig.json

@@ -0,0 +1,19 @@
+{
+  "compilerOptions": {
+    "outDir": "dist",
+    "baseUrl": ".",
+    "module": "CommonJS",
+    "target": "ES2017",
+    "lib": ["ESNext", "DOM", "DOM.Iterable"],
+    "moduleResolution": "Node",
+    "sourceMap": false,
+    "declaration": false,
+    "strict": false,
+    "noImplicitAny": true,
+    "skipLibCheck": true,
+    "esModuleInterop": true,
+    "allowSyntheticDefaultImports": true,
+    "experimentalDecorators": true,
+    "jsx": "react"
+  }
+}