Bascally, we reach into the old location in secret storage and if we find sessions (with a refresh token) we seed that in the MSAL world.
We do this one time... unless they switch back to the old world and then switch to the new world.
This has two different behaviors depending on if the Broker is used:
* If the broker is not used, this does what you might expect. It makes it seem totally transparent to the user that something has changed. All sessions get migrated over and the user is still logged in to what they were previously.
* If the broker is used... you don't get automatically logged in _unless_ you have already logged in to that account at the OS level. So this helps skip the "VS Code access layer" outlined in `accountAccess.ts`. Not as good as the previous bullet, but this is the best we can do in the broker world.
In time, we can remove this migration along with the old way of doing things.
Tyler James Leonhardt
e5079d8a05