move to new signing process for release build and prep for 1.20.0

[JamesWTruher]

PR Summary

The infrastructure at MS has changed with regard to signing, this PR allows us to use it.

PR Checklist

• PR has a meaningful title
  • Use the present tense and imperative mood when describing your changes
• Summarized changes
• Change is not breaking
• Make sure all .cs, .ps1 and .psm1 files have the correct copyright header
• Make sure you've added a new test if existing tests do not effectively test the code changed and/or updated documentation
• This PR is ready to merge and is not Work in Progress.
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[bergmeister]

looks good but the build seems to be broken. Also wondering whether 1.20.0 would be a better target version since the changes are all small improvements but not fixes

[JamesWTruher]

I've rebased to be up to date.

@bergmeister, @rjmholt, @SydneyhSmith - Chris is suggesting that our next release should perhaps be number 1.20.0 and I wanted everyone to have a chance to provide an opinion. FWIW, I'm ok with 1.20

[rjmholt]

LGTM -- agree that 1.20 seems good

[TravisEz13]

looks about right to me

[rjmholt]

Generally looks good, just a small comment about the Write-Host invocations