Token calculation fix for Get-Help executed on ScriptBlock.

[hubuk]

Fix for #8234

PR Summary

Changed token calculation for Get-Help cmdlet.
Added test case for function dynamically created from script block.

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 .h, .cpp, .cs, .ps1 and .psm1 files have the correct copyright header
• 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.
• User-facing changes
  • Not Applicable
  • OR
  • User-facing Documentation needed
    • Issue filed - Issue link:
• Testing - New and feature
  • Not Applicable or can only be tested interactively
  • OR
  • Make sure you've added a new test if existing tests do not effectively test the code changed
    • Add [feature] if the change is significant or affects feature tests

[adityapatwardhan]

@hubuk I have pushed a commit with [Feature] tag according to https://github.com/PowerShell/PowerShell/blob/master/docs/testing-guidelines/testing-guidelines.md#requesting-additional-tests-for-a-pr

The new test is part of a Describe which is marked as Feature. Hence, this was required.

[hubuk]

Thanks, I can add [Feature] prefix to the message in my commit. Would you like me to do it instead and rebase my commit?

[adityapatwardhan]

@hubuk Don't worry about rebasing. I pushed an empty commit with [Feature] and we usually squash and merge.

I have restarted the CI on AppVeyor to pick up the fixes for the unrelated failing test.

[adityapatwardhan]

@hubuk Thank you for your contribution!