Make limactl ls --format yaml use the same schema as the json output

[jandubois]

Fixes #3984

It makes sure YAML uses the same key names as JSON for the 4 host properties, and it inlines the instance properties into the root object:

❯ l ls default --format json | yq .HostOS
darwin

❯ l ls default --format yaml | yq .HostOS
darwin

❯ l ls default --format json | yq .config.user
{"name": "jan", "comment": "Jan Dubois", "home": "/home/jan.linux", "shell": "/bin/bash", "uid": 501}

❯ l ls default --format yaml | yq .config.user
name: jan
comment: Jan Dubois
home: /home/jan.linux
shell: /bin/bash
uid: 501

[jandubois]

Just noticed that this PR does not include this part of my suggested solution:

• We add the 4 host settings to limactl info output

I would still like to hear some feedback if that is what we want to do. I can add it to this PR, or create a separate one...

[jandubois]

• We add the 4 host settings to limactl info output

I've added hostArch, hostOS, and identityFile to limactl info (it already has limaHome).

I lower-cased the key names to match the existing naming scheme for limactl info output.

[jandubois]

I've added one more commit to "deprecate" the host fields, so they don't show up in limactl ls --list-fields, but still exist in the JSON object:

❯ l ls default --json | yq .HostOS
darwin
❯ l ls --list-fields | grep HostOS
❯ 

[AkihiroSuda]

Thanks