Deploy Azure KeyVault (Premium, RBAC)

[ExchMaster]

Description

Added an example bicep template which enables the deployment of Azure Key Vault. The Key Vault will deploy into default MLZ resource groups using default MLZ naming conventions unless those values are overwritten at run time via parameters.

The key vault will deploy enabled for RBAC and using the premium SKU for HSM backed keys.

This update uses the bicep shared variable file pattern as described here: https://docs.microsoft.com/en-us/azure/azure-resource-manager/bicep/patterns-shared-variable-file

Issue reference

This PR is related to the following issue: #517
I did attempt to retrieve MLZ outputs using a deployment object, but ultimately failed to successfully do so do the dynamic nature of how the outputs are parsed/discovered at run-time. More research is needed, but felt this pattern solved the majority of the issue and is worthy of doing now while we continue to investigate how to use deployment objects for this problem.

Checklist

Please make sure you've completed the relevant tasks for this PR out of the following list:

• [see above] All acceptance criteria in the backlog item are met
• [ x] The documentation is updated to cover any new or changed features
• [ x] Manual tests have passed
• [ x] Relevant issues are linked to this PR

[brooke-hamilton]

@ExchMaster thank you! 🥇