[dashboard] Websocket is not reconnectable in iframe

[AlexTugarev]

Bug description

When not being logged in to Gitpod and trying to access a URL of a running workspace you will see the login page, but after signing in with OAuth you will stay on the login page.

Steps to reproduce

1. Start a workspace and copy it's URL
2. open a clean browser session (where you are not logged in at that time) and try to access the workspace URL
3. try to login

Expected behavior

After a successful login, you would be able to access your workspace from a clean browser session.

Example repository

No response

Details

• When not being logged in to Gitpod and trying to access a URL of a running workspace the websocket is created in the supervisor frontend instead of the regular dashboard parts.
• Supervisors frontend is not prepared for reconnecting websockets (Websocket reconnect not possible is logged)
• Also it seems there were related changes merged to gitpod-protocol in the meantime which needs to be considered.

Workaround

• forcibly reload the browser tab (with the workspace URL) after the login in order to recreate the websocket connection

/cc. @akosyakov