Add connected workspaces to agent details
MR: Pending
<!--
The first line of the MR must be one of the following:
1. `MR: Pending`
2. `MR: <MR link with trailing +>`,
and the first description line of the MR should be `Issue: <Issue link with trailing +>`
3. `MR: No MR`
For more context, see:
https://about.gitlab.com/handbook/engineering/development/dev/create/ide/index.html#1-to-1-relationship-of-issues-to-mrs
-->
<!--
The following sections should be filled out as part of the refinement process before the issue is prioritized.
For more context, see:
https://about.gitlab.com/handbook/engineering/development/dev/create/ide/#2-pre-iteration-planning-meeting
-->
## Description
During IPM discussions it was decided to split off the `Connected Workspaces` field from the rest of the proposed `Agent Details` popover in https://gitlab.com/gitlab-org/gitlab/-/issues/444859. This issue is focused on refining the design and implementation details.
JTBD we are targeting:
- When making agent mapping decisions, I want to see the current state of an agent so I can understand the impact my decisions will have on my team's workspace users.
Target UX outcome:
- Users can accurately predict the impact unmapping an agent will have on existing workspaces.
## Acceptance Criteria
TODO: Fill out (required)
- [ ] We have a clear definition of what qualifies as a connected workspace
- [ ] [Describe another requirement needed to complete this issue.]
- [ ] [Add additional acceptance criteria as needed.]
## Technical Requirements
TODO: Fill out or delete
[If applicable, please list out any technical requirements for this feature/enhancement.]
## Design Requirements
TODO: Fill out or delete
[If applicable, please provide a link to the design specifications for this feature/enhancement.]
<!-- Replace with other type, e.g. bug or maintenance, if appropriate -->
<!-- Replace with other subtype if appropriate -->
<!-- By default, all issues start in the unprioritized status. See https://about.gitlab.com/handbook/engineering/development/dev/create/ide/#-remote-development-planning-process -->
<!-- For simplicity and to avoid triage bot warnings about missing workflow labels, we will default to issues starting at the refinement phase -->
issue