Feat: track Azure VM Galleries

[dduportal]

Follow up of jenkins-infra/packer-images#232.

This PR adds tracking, by terraform, of the Azure VM Shared Library images.

• The 3 missing images will be created once this PR is merged: staging_ubuntu-20.04, staging_windows-2022, `prod_windows-2022
• All the other shared library had been imported with terraform import <...> <...> commands in the production state
• Tags are added to all resource to help us tracking the terraform managed resources
• Please note that some elements are located in US East 2: it's a bit of a mess, because it's the production, and Azure refused to migrate these items to US East. As I did not want to break the production, I've used a local to map the regions per gallery and image: it adds a bit of complexity in the code alas

This PR also adds 2 "chore" changes:

• Updated the gitignore and .shared-tools to latest setttings
• Ensure that the pgsql's subnet is not updated on each terraform run, by fixing the changed setting

[infra-ci-jenkins-io]

Report for "feat: track azure VM image galleries"

Plan parsing method

💰 Infracost estimate: monthly cost will increase by $0.50 📈

Project	Previous	New	Diff
jenkins-infra/azure/.	$0	$0.50	+$0.50

Infracost output

Project: jenkins-infra/azure/.

+ azurerm_postgresql_flexible_server.public
  $0.00

    + Compute (B_Standard_B1ms)
      $0.00

    + Storage
      $0.00

+ azurerm_private_dns_zone.public_pgsql
  +$0.50

    + Hosted zone
      +$0.50

Monthly cost change for jenkins-infra/azure/.
Amount:  +$0.50 ($0.00 → $0.50)

──────────────────────────────────
Key: ~ changed, + added, - removed

25 cloud resources were detected:
∙ 2 were estimated, 1 of which usage-based costs, see https://infracost.io/usage-file
∙ 8 were free:
  ∙ 3 x azurerm_resource_group
  ∙ 2 x azurerm_private_dns_zone_virtual_network_link
  ∙ 1 x azurerm_network_security_group
  ∙ 1 x azurerm_subnet
  ∙ 1 x azurerm_subnet_network_security_group_association
∙ 15 are not supported yet, see https://infracost.io/requested-resources:
  ∙ 12 x azurerm_shared_image
  ∙ 3 x azurerm_shared_image_gallery

[dduportal]

Terraform plan looks as expected