PR Summary

This adds completion for the various parameters and their values for #requires statements.
For example: #requires -PSEdition Core -RunAsAdministrator

The following parameters are supported:

• Version
• Modules
• PSEdition
• RunAsAdministrator

The following parameters are not supported because they have been deprecated or don't work:

• PSSnapin
• ShellId
• Assembly

Most of the help text has been taken from the official docs but I took some creative liberties for the PSEditions text.

I'm not sure how strict the completion should be.
Currently it will prevent some basic mistakes like adding parameters after RunAsAdministrator but there's no special checks for randomly inserted characters so if for example you type: #requires blabla -<Tab> it will still complete to the next parameter.

PR Context

The easier the requires statements are to use, the more likely it is that people will use them. The Modules parameter in particular is hard to use without looking up the documentation due to the hashtable keys you have to remember when specifying a version.

PR Checklist

• PR has a meaningful title
  • Use the present tense and imperative mood when describing your changes
• Summarized changes
• 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.
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• Breaking changes
  • None
  • OR
  • Experimental feature(s) needed
    • Experimental feature name(s):
• User-facing changes
  • Not Applicable
  • OR
  • Documentation needed
    • Issue filed:
• Testing - New and feature
  • N/A 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
• Tooling
  • I have considered the user experience from a tooling perspective and don't believe tooling will be impacted.
  • OR
  • I have considered the user experience from a tooling perspective and enumerated concerns in the summary. This may include:
    • Impact on PowerShell Editor Services which is used in the PowerShell extension for VSCode (which runs in a different PS Host).
    • Impact on Completions (both in the console and in editors) - one of PowerShell's most powerful features.
    • Impact on PSScriptAnalyzer (which provides linting & formatting in the editor extensions).
    • Impact on EditorSyntax (which provides syntax highlighting with in VSCode, GitHub, and many other editors).