Set Assembly version attribute for 1.19.1 release

[JamesWTruher]

PR Summary

this change puts an assembly version on the analyzer assemblies, so you can see the version by inspection of the assembly

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.
  • If the PR is work in progress, please add the prefix WIP: to the beginning of the title and remove the prefix when the PR is ready.

[rjmholt]

We should also set the version for Microsoft.PowerShell.CrossCompatibility.

Ideally in future we can use a more centralised configuration, like PSScriptAnalyzer.Common.props or something, to set this in one place. We possibly also discussed a YAML configuration for this

[bergmeister]

Yes to doing it also for Microsoft.PowerShell.CrossCompatibility.dll. Please update the changelog with this PR.

I am not sure why (and if) we need the existing VersionPrefix property, which is also not present in Microsoft.PowerShell.CrossCompatibility.dll at the moment