{VirtualWan} Mark older routeTable cmdlets as deprecating

[nagula-ritvika]

Description

We will not be supporting the cmdlet for rtv1 and rtv2 anymore and have already moved all cx to the new routing infra.Marking older cmdlets as deprecating and pointing to new cmdlets.

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)
  • the markdown help files have been regenerated using the commands listed here

[isra-fel]

Changes look good to me. Please just update network's changelog. Thanks

[nagula-ritvika]

@isra-fel updated the change log, thank you

[isra-fel]

LGTM

[isra-fel]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 3 pipeline(s).

[isra-fel]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 3 pipeline(s).

[isra-fel]

/azp run azure-powershell - powershell-core

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).