Copy To functionality for notebooks (#141)

* Add Copy To functionality for notebooks

* Fix formatting

* Fix linting errors

* Fixes

* Fix build failure

* Rebase and address feedback

* Increase test coverage

src/Utils/Base64Utils.ts

@@ -0,0 +1,7 @@
+export const utf8ToB64 = (utf8Str: string): string => {
+  return btoa(
+    encodeURIComponent(utf8Str).replace(/%([0-9A-F]{2})/g, (_, args) => {
+      return String.fromCharCode(parseInt(args, 16));
+    })
+  );
+};