PRs do not refresh after changing account preferences in dropdown

[rzhao271]

Testing microsoft/vscode#229420

On https://insiders.vscode.dev/github/microsoft/vscode, I logged into two GitHub accounts by signing into one for one extension and signing into an alt one for another extension.
I switched from my main account to the alt account for GHPRI by going to the extension preview, clicking on the gear icon, and selecting Account Preferences.
Then, I pressed refresh on the pull request viewlet, expecting the "Created By Me" section to go blank, but my main account PR was still there.

[alexr00]

Super cool that this is supported now! Looks like it needs adoption. @TylerLeonhardt FYI, I'll try to do it in October.