Allow tasks to access production via temporary maintainer tokens

[rocketeerbkw]

Checklist

• Affected Issues have been mentioned in the Closing issues section
• Documentation has been written/updated.
• Changelog entry has been written

With the RBAC changes, access to the API via cli containers was given via guest permissions. This prevented the tasks from doing syncs from production environments. This PR adds a default maintainer user to every project, with no password and no ssh key (so logins with this user aren't allowed). Additionally, the api client requests a new access token for the maintainer and passes that to the task container. The ssh server was modified to allow passing a LAGOON_TOKEN environment variable that it will uses to check permissions.

Changelog Entry

Improvement - Allow tasks to access production via temporary maintainer tokens (#1229)
Bugfix - Prevent lagoon images from interfering with pygmy

Closing issues

closes #1229

[Schnitzel]

@rocketeerbkw can you fix the conflict? thank you

[tobybellwood]

default-uisers were given maintainer access a while back, closing!