Add container labels for the runtime major/minor and SDK versions

[baronfel]

For provenance/security scanner purposes it would help if .NET images surfaced their runtime major/minor and SDK tooling versions. We propose:

• net.dot.runtime.majorminor - the TFM version this app is running on
• net.dot.sdk.version - the SDK major.minor.patch that was used to build this image

We're using net.dot as a prefix because we own/control the https://dot.net URI, and these are not intended to be labels constrained to the Microsoft-shipped .NET SDKs, but also for any SDKs built by our Source-Build partners and their users.

[richlander]

Another name is net.dotnet. I'm not saying that's better, but an option. It's shorter and less Microsoft.

[baronfel]

I dig it. I was leaning more in the 'this is Microsoft's opinion' line of thinking with the naming, but I'm not opposed to something more general.

[samsp-msft]

We should "own" the domain name for whatever we use. http://dotnet.net does not appear to be owned by us, and is a blog last updated in 2007. The point of the naming scheme is to prevent collisions. I think we are safest with com.microsoft.dotnet.

[richlander]

Sorry. I meant net.dot. That said, I'm fine with either option.

[baronfel]

Closing as we've implemented this for 8.0.300.