Keyvault full backup/restore support

[gearama]

Pull Request Checklist

Please leverage this checklist as a reminder to address commonly occurring feedback when submitting a pull request to make sure your PR can be reviewed quickly:

See the detailed list in the contributing guide.

• [ ] C++ Guidelines
• [ ] Doxygen docs
• [ ] Unit tests
• [ ] No unwanted commits/changes
• [ ] Descriptive title/description
  • [ ] PR is single purpose
  • [ ] Related issue listed
• [ ] Comments in source
• [ ] No typos
• [ ] Update changelog
• [ ] Not work-in-progress
• [ ] External references or docs updated
• [ ] Self review of PR done
• [ ] Any breaking changes?

[gearama]

/azp run cpp - keyvault

[azure-pipelines[bot]]

Azure Pipelines successfully started running 1 pipeline(s).

[gearama]

/azp run cpp - keyvault

[azure-pipelines[bot]]

Azure Pipelines successfully started running 1 pipeline(s).