Add nanoserver ltsc2019 along with 1809

[dduportal]

What feature do you want to see added?

As per https://learn.microsoft.com/en-us/windows-server/get-started/servicing-channels-comparison and https://hub.docker.com/_/microsoft-windows-nanoserver, we should provide an LTSC2019 for nanoserver in replacement of 1809.

That would ensure our users always have the latest stable content from the OS base image, ant it would help us for maintenance (ref. https://github.com/jenkinsci/docker-agent/pull/445/files#r1254304996 for instance).

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This would impact the published tags by changing the suffix 1809 by ltsc2019.

It means we also want to introduce a set of (additional) new tags such as jdk11-nanoserver, 3107.v665000b_51092-16-jdk11-nanoserver, etc. like we are already doing with the Linux image while keeping the existing ones.

Note that https://docs.docker.com/compose/compose-file/build/#tags could GREATLY help in that matter

[dduportal]

Editing issue title: we want both 1809 (to keep existing images) in addition to the new ltsc2019.

[lemeurherve]

Reopening as the suggestion done in #475 for adding it in another PR hasn't been applied.

Should be closed by #488