fix: add custom external name configuration for cloud_project_storage

[fabiencastarede]

Description

Adds custom external name configuration for the ovh_cloud_project_storage resource to support the patched OVH Terraform provider that properly populates the ID field.

Problem

The ovh_cloud_project_storage resource requires custom external name configuration because:

1. The OVH Terraform provider is being updated to populate the ID field with composite format: service_name/region_name/name
2. The external name (Kubernetes resource name) should only be the bucket name
3. Import operations require the full composite ID format

Without this configuration, the resource cannot:

• Extract the correct external name from Terraform state
• Construct proper import IDs for existing resources
• Map between Crossplane and Terraform naming correctly

Changes

config/external_name.go

• Add storageIdentifierFromProvider configuration with:
• GetExternalNameFn: Parses composite ID and extracts bucket name (last component)
• GetIDFn: Constructs composite import ID from parameters (service_name/region_name/name)
• Input validation for ID format
• Add ovh_cloud_project_storage to ExternalNameConfigs map

config/cloud/config.go

• Add resource configurator to set ShortGroup = "cloud" for storage resource
• Enables proper resource organization

How It Works

During resource creation:

1. User creates ProjectRegionStorage with metadata.name: my-bucket
2. Terraform creates bucket, provider sets ID to service123/GRA/my-bucket
3. GetExternalNameFn extracts my-bucket as external name

During import:

1. User specifies external name: my-bucket with parameters
2. GetIDFn constructs import ID: service123/GRA/my-bucket
3. Terraform imports using composite ID format
4. GetExternalNameFn extracts bucket name for Crossplane

Depends On

This configuration works with the patched OVH Terraform provider pending PRs at https://github.com/ovh/terraform-provider-ovh:

• Populate ID field in Create/Read/Update operations
• Handle 404 errors properly in Read operation

Until those PRs are merged, users can use a locally patched provider via filesystem mirror.

Testing

Tested with patched provider (v2.9.0):

• ✅ Resource creation
• ✅ Resource updates
• ✅ Resource deletion
• ✅ Import existing resources
• ✅ Drift detection and reconciliation

Example Usage

apiVersion: cloud.ovh.upbound.io/v1alpha1
kind: ProjectRegionStorage
metadata:
name: my-bucket
spec:
forProvider:
  serviceName: "my-service-id"
  regionName: GRA
providerConfigRef:
  name: default

Results in:
- Terraform ID: my-service-id/GRA/my-bucket
- External name: my-bucket
- Import ID: my-service-id/GRA/my-bucket