[Storage] Support new SRP features on new API version 2021-06-01

[blueww]

Description

Design pass review:
New Schema field in Blob inventory: https://github.com/Azure/azure-powershell-cmdlet-review-pr/issues/924#issuecomment-913448643
PublicNetworkAccess : https://github.com/Azure/azure-powershell-cmdlet-review-pr/issues/1027
rootsquash on create/update container: https://github.com/Azure/azure-powershell-cmdlet-review-pr/issues/1029
AllowProtectedAppendWriteAll : https://github.com/Azure/azure-powershell-cmdlet-review-pr/issues/1028

Checklist

• I have read the Submitting Changes section of CONTRIBUTING.md
• The title of the PR is clear and informative
• The appropriate ChangeLog.md file(s) has been updated:
  • For any service, the ChangeLog.md file can be found at src/{{SERVICE}}/{{SERVICE}}/ChangeLog.md
  • A snippet outlining the change(s) made in the PR should be written under the ## Upcoming Release header -- no new version header should be added
• The PR does not introduce breaking changes
• If applicable, the changes made in the PR have proper test coverage
• For public API changes to cmdlets:
  • a cmdlet design review was approved for the changes in this repository (Microsoft internal only)
    • {See Above}
  • the markdown help files have been regenerated using the commands listed here