normalise ID flags

[benabineri]

Description of change

This is somewhat speculative but I was dismayed by this:

resim --auth-url=https://resim-dev.us.auth0.com/ --url=https://api.resim.io/v1/ --project image-testing systems get --id 8ecf89d8-56b0-46da-8e67-46dd1f04c6d9 
2025/08/15 14:15:57 unknown flag: --id
resim --auth-url=https://resim-dev.us.auth0.com/ --url=https://api.resim.io/v1/ --project image-testing systems get --system-id 8ecf89d8-56b0-46da-8e67-46dd1f04c6d9
2025/08/15 14:16:03 unknown flag: --system-id
resim --auth-url=https://resim-dev.us.auth0.com/ --url=https://api.resim.io/v1/ --project image-testing systems get --system 8ecf89d8-56b0-46da-8e67-46dd1f04c6d9 
<the system>

This change makes them all work.

Guide to reproduce test results

Checklist

• I have self-reviewed this change.
• I have tested this change.
• This change is covered by tests that are already landed, or in this PR.
• I have updated the changelog, if appropriate.

[iainjwhiteside]

i don't think we can be so general about this and have it work completely correctly (partly due to issues with our current implementations).

For example, most places where we have batch it's either batch-name or batch-id explicitly. For builds, it's only ever build-id. I think for this to work for those, we'd need to make some further changes?