feat(ovhcloud-cli): refactor all storage commands

[Gandalf-Le-Dev]

Description

Restructure all storage CLI commands, add volume edit capabilities (retype + resize), and harmonize naming with Manager/API.

Command hierarchy restructure — Created a parent storage command under cloud that groups all storage subcommands:

• cloud storage-block → cloud storage block
• cloud storage-file → cloud storage file
• cloud storage-s3 → cloud storage object
• cloud storage-swift → cloud storage swift

Volume retype — Added --type flag to cloud storage block edit allowing volume type changes via the region-scoped PUT endpoint.

Volume resize via edit — Added --size flag to cloud storage block edit, replacing the dedicated upsize command. The region-scoped PUT endpoint (/v1/cloud/project/{id}/region/{region}/volume/{volumeId}) handles both retype and resize.

Removed upsize command — Resize is now handled by edit --size, aligning with the API which uses a single PUT endpoint for all volume updates.

Edit command only sends changed fields — The edit command builds its PUT body from explicitly provided flags only, avoiding unintended side effects (e.g., sending an unchanged size would trigger a resize validation error from the API).

Type of change

• New feature (non-breaking change which adds functionality)
• Improvement (improvement of existing commands)
• Breaking change (fix or feature that can break a current behavior)

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