conductor: Add support for Azure Backup and Restore

[ianstanton]

This PR adds steps for creating the Azure 'IAM' resources necessary for instances to perform backup / restore with Azure Blob Storage.

When an instance using Azure is created:

• Creates User Assigned Managed Identity
• Creates Role Assignment
• Creates Federated Credentials
• Passes relevant info as part of the CoreDB spec

When an instance using Azure is deleted:

• Deletes the User Assigned Managed Identity

Note: This only supports the backup archive bucket at the moment. We'll add support for the storage archive bucket as a follow-up

[nhudson]

Might be good to add a check like these to make sure you can't set aws or gcp also at the same time. Other than that LGTM! Great work!

    // Error and exit if both IS_CLOUD_FORMATION and IS_GCP are set to true
    if is_cloud_formation && is_gcp {
        panic!("Cannot have both IS_CLOUD_FORMATION and IS_GCP set to true");
    }

    // Error and exit if IS_GCP is true and GCP_PROJECT_ID or GCP_PROJECT_NUMBER are not set
    if is_gcp && (gcp_project_id.is_empty() || gcp_project_number.is_empty()) {
        panic!("GCP_PROJECT_ID and GCP_PROJECT_NUMBER must be set if IS_GCP is true");
    }

[ianstanton]

Might be good to add a check like these to make sure you can't set aws or gcp also at the same time. Other than that LGTM! Great work!

    // Error and exit if both IS_CLOUD_FORMATION and IS_GCP are set to true
    if is_cloud_formation && is_gcp {
        panic!("Cannot have both IS_CLOUD_FORMATION and IS_GCP set to true");
    }

    // Error and exit if IS_GCP is true and GCP_PROJECT_ID or GCP_PROJECT_NUMBER are not set
    if is_gcp && (gcp_project_id.is_empty() || gcp_project_number.is_empty()) {
        panic!("GCP_PROJECT_ID and GCP_PROJECT_NUMBER must be set if IS_GCP is true");
    }

Thanks, good suggestion! Addressed here a4b9cd5