This change is broken down from a very large MR:
https://gitlab.com/gitlab-org/gitlab/-/merge_requests/22719

The overall goal is to convert the Geo Node Form from HAML to Vue
Based on MVC, splitting this into smaller MRs is more feasible

This MR adds the next piece of the Geo Form to Vue
- Selective Sync (Select Field)
- Selective Sync Shards (Multi-Select Dropdown)

There is another type of Selective Sync (Namespaces)
This will be added in the next MR