Update "Tip" notification for new users to either show the existing tip, a link to a feedback survey or nothing (microsoft#13554)

* Update vscode-tas-client
* Add experiment group enum
* Add method to retrieve experiment values
* Implementation + tests
* News file
* Update wording of the news entry
* Add telemetry
* More tests
* No opting-in and out of this one
* Don't fetch value if opted out, add tests
* Address comments

Author: kimadeline

news/1 Enhancements/13535.md

@@ -0,0 +1 @@
+Update "Tip" notification for new users to either show the existing tip, a link to a feedback survey or nothing.