Add hostname support (GET/POST)

[chiconws]

Summary

This PR adds hostname endpoint support to the Python NanoKVM client.

Changes

• Added GET /vm/hostname support via get_hostname()
• Added POST /vm/hostname support via set_hostname(hostname)
• Added typed models:
  • GetHostnameRsp
  • SetHostnameReq

Notes

• SetHostnameReq.hostname includes the note that the change applies after reboot.

[chiconws]

Hey @puddly ! Thanks for the approval. Can you also merge it?
I'm using this endpoint on the Home Assistant Integration soon.

[puddly]

Done. I've invited you to the repo as a collaborator as well, since you're maintaining the Home Assistant integration.

[chiconws]

Thanks for the invite, I appreciate the trust.
I’ll keep pushing small improvements and will ask for review on larger changes.