feat: add ovh_vrackservices resource

[chaufmaurice]

Description

Add a resource for Vrack Services product.

Type of change

• New feature (non-breaking change which adds functionality)
• [x ] Documentation update

How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Provide instructions so we can reproduce. Please also list any relevant details for your test configuration

• Test A: make testacc TESTARGS="-v -run TestAccResourceVrackServices_basic"

Test Configuration:

• Terraform version: terraform version: Terraform v1.14.0

# Checklist:

- [x] My code follows the style guidelines of this project
- [x] I have performed a self-review of my code
- [x] I have commented my code, particularly in hard-to-understand areas
- [x] I have made corresponding changes to the documentation
- [x] My changes generate no new warnings or issues
- [x] I have added acceptance tests that prove my fix is effective or that my feature works