More selective sharing of Observable Secrets with Team Guests

[zachperiscopic]

Is your feature request related to a problem? Please describe.
We have been using Observable Secrets as a way to store API keys to access data sources. We can then share notebooks with people by making them Guests, and allowing guest access for selective Secrets. However, this means that all Guests for our Team will have access to every Secret with Guest Access. In other words, there is no way to be more selective with sharing Secrets, such as specifying which guests can access which secrets beyond a global "Guest Access". This means Guests could potentially access Secrets we'd rather not share with all Guests to our Team.

Describe the solution you'd like

• Team Editors or Team Owners can create Observable Secrets and share them with specific Guests
• Observable Secrets are available to all Team members
• Could extend to Team Owner having ability to create Secrets shared only with specific Team members, but mostly it's about Guests for me, being selective rather than handing over all Secrets with Guest access.

Describe alternatives you've considered

• Separate accounts for specific clients, but that feels kinda messy

Additional context

• This is a specific case which certainly applies to a larger discussion on #305
• Example snapshot below from Secrets page, with global switch for guest access set to "Yes" (last column). Overall, would be awesome to be able to choose the guests I want to invite to the party, as it were.