[teams] Allow limiting shareability

[svenefftinge]

Team owners should be able to limit sharing functionality (live share and snapshots) for workspaces started on any of their projects. I see the following three settings:

• Share with anyone (default)
• Share only with team members
• No Sharing

[gtsiolis]

Cross-posting #4112 and a relevant discussion (internal).

Also, maybe it could be worth considering to share only with team members by default and allow users to manually switch to share with anyone with a link. 💡

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[gtsiolis]

Reopening as this is still relevant. Cc @jldec @geropl