Fetch the ms.service from some source of truth

[sima-zhu]

The docs ms.service is currently set to service directory and not able to override if it is wrong value.

Needs to fetch the value from other source of truth.

Proposal:

1. Add 'ms.service' to csv data, so team can update value there, if no value, then defaults to service directory.

Long-term goal:

1. Align and sync the value with Taxonomies service: https://review.docs.microsoft.com/en-us/help/contribute/metadata-taxonomies?branch=main#msservice

[sima-zhu]

https://github.com/Azure/azure-sdk/pull/4014/files

[weshaggard]

When you add this column to the csv script please name it as MSDocService and add it readme file https://github.com/Azure/azure-sdk/blob/main/eng/README.md and also initialize it in https://github.com/Azure/azure-sdk/blob/main/eng/scripts/PackageList-Helpers.ps1#L43.

[sima-zhu]

#2910

[sima-zhu]

#1442

[sima-zhu]

The issue has been fixed which we have a way to override the value in csv file. Closed the issue and open a new one for future use case