Make existing integrations visible to users who didn't set them up

[charlesmathias]

Only users who set up integrations can see that the integrations have been set up. This may cause some confusion.

I think we should make all existing team integrations visible to all team members, but only editable by the member who set them up.

The team lead (and the Org Admin, if there is one) can remove any existing integrations.

Here's a related idea for removing all integrations across all teams, as an Enterprise security feature:
#10227

Example case of the confusion mentioned above:

I’m a team member and I’ve created a retro. I want the team to add reflections ahead of a sync meeting next week. From what I can see on my team settings, there is no Slack integration. I choose not to connect. I set a timer and choose not to “Notify Team via Slack”, leaving that unticked. If there is already a Slack connection set up (that I can’t see), a channel will be notified on Slack despite me leaving that option unticked.
On the other hand, if I did want to send a notification, I have to set up a new Slack integration, which may be duplicating messages.

[Dschoordsch]

I think it would make sense in this context to give other team members the option to change some settings. If we look at Slack

I suggest we keep all the individual on/off settings accessible to everyone, but disable the channel dropdown and replace the dot-menu with an info icon with a tooltip 'User Bob added this integration' in case they want to remove it or something.

[Dschoordsch]

I did not look into the "Private Notifications" part, so I don't know how to handle that one yet.