✨ feat(metadata): add net and role labels on nodes

[jfbus]

Description

This PR adds labels on nodes:

• net ID (can be used to target loadbalancer backend nodes in multi-VPC clusters),
• role (as defined by the Outscale Cluster-API provider).

labels:
  topology.outscale.com/net: vpc-xxx
  role.outscale.com/worker: ""

Note: as the role may be a user-defined value, the standard node-role.kubernetes.io/<role> label is not used.

Refs: #568

Type of Change

Please check the relevant option(s):

• 🐛 Bug fix
• ✨ New feature
• 🧹 Code cleanup or refactor
• 📝 Documentation update
• 🔧 Build or CI-related change
• 🔒 Security fix
• Other (specify):

How Has This Been Tested?

Please describe the test strategy:

• Manual testing
• Unit tests
• E2E tests
• Not tested yet

Checklist

• I have followed the Contributing Guidelines
• I have added tests or explained why they are not needed
• I have updated relevant documentation (README, examples, etc.)
• My changes follow the Conventional Commits specification
• My commits include appropriate Gitmoji

Additional Context