Update templates for external SDK

The external SDK needs to be imported manually by the user in their `profile.ps1`. We will need to update our templates to demonstrate how to do this.

We will need to modify the templates for VSCode, and core-tools. There may be more template sources in other places as well that will need updating.

Start by locating the VSCode and core-tools templates and inspect how each generates the user's profile.ps1. Check for other template sources in the repository that need the same external SDK import example. Done means all relevant templates demonstrate the manual import consistently.

Written by the indexing model from the issue text.