feat(ovhcloud-cli): migrate instance list/get/delete/set-name to API v2

[Bxota]

Description

First step of the instance migration to API v2: instance list, get, delete and set-name now use /v2/publicCloud/project/{projectId}/compute/instance[/{instanceId}]. The other instance subcommands stay on v1 and will be migrated in follow-up PRs.

• list: a single v2 call returning full objects, instead of listing IDs then fetching each instance. Columns: id, name, region, powerState, status
• get: template rewritten on the v2 envelope (status, power state, region/AZ, SSH key, lock, IP addresses with type and network, flavor, image, volumes, security groups, current tasks)
• set-name: same command and arguments; fetches the instance, changes targetSpec.name and sends back the editable targetSpec with the checksum. Adds --wait
• delete: asynchronous in v2, the message is now "Instance X is being deleted"
• Shell completions of the instance commands now use the v2 listing (instance group completions stay on v1)
• Resync the two instance routes and the schemas they reference in cloud_v2.json with the live spec
• Tests for the 4 commands, including a CREATING instance with no currentState, an instance without image, the set-name PUT body, --wait and a 404

Manually tested on a real v2 instance (create via API v2, then list / get / set-name --wait / delete).

Breaking changes

• instance list no longer has a flavor.name column (only available in currentState, shown by get)
• --filter expressions on instance list apply to the v2 envelope: name=="x" becomes targetSpec.name=="x", region becomes targetSpec.location.region
• IAM: set-name now requires publicCloudProject:apiovh:instance/edit, and list/get/delete the v2 instance/get / instance/delete actions

Type of change

• Improvement (improvement of existing commands)
• Breaking change (fix or feature that can break a current behavior)
• Documentation update

Checklist:

• My code follows the style guidelines of this project
• I have commented my code
• I ran go mod tidy
• I have added tests that prove my fix is effective or that my feature works