[CDF-25405] Fix support dumping multiple groups (#1819)

# Description

Fixes the `cdf dump group` command such that the user can select
multiple groups and not just one at a time. **Note** This command did
not have any tests so I introduced tests for it.

<img width="1153" height="503" alt="image"
src="https://github.com/user-attachments/assets/0c21addc-775e-449c-a71f-8acdd0713ede"
/>

## Changelog

- [x] Patch
- [ ] Minor
- [ ] Skip

## cdf

### Fixed

- When running command `cdf dump group` you can now select multiple
groups.

## templates

No changes.
