Update PackageVersion comments to use /** */ form instead of /// form

[LarryOsterman]

The following azure packages have /// form comments in their package_version.hpp file:
X * Azure::Attestation
X* Azure::Core
X* Azure::Identity
X* Azure::Keyvault::Secrets
X* Azure::Keyvault::Keys
X* Azure::Keyvault::Certificates
X* Azure::Storage::Blobs
X* Azure::Storage::Common
X* Azure::Storage::Files::Datalake
X* Azure::Storage::Files::Shares
X* Azure::Storage::Queues
X* Azure::Template

They should be updated to reflect coding guidelines and use the /** */ form of comments.

Originally posted by @LarryOsterman in #3561 (comment)

[Jinming-Hu]

What's the motivation of this proposal?

Javadoc style comments (/** */) are for doxygen docs. If I write some comments just for developers to better understand the code logic, it shouldn't be reflected in doxygen docs.

[LarryOsterman]

I'm going to let @gearama comment on the motivation. He's the one who raised the issue of /// doxygen comments in a code review.

I'm just the messenger here.

[Jinming-Hu]

Okay, so you are not talking about all the comments, just doxygen comments.

There are four styles listed in the manual https://www.doxygen.nl/manual/docblocks.html. If you're only talking about doxygen comments, then I agree, we should have consistent style.