The current powershell completion is not very capable.
Let's port it to the go custom completion logic to have a
unified experience accross all shells.
Powershell supports three different completion modes
- TabCompleteNext (default windows style - on each key press the next option is displayed)
- Complete (works like bash)
- MenuComplete (works like zsh)
You set the mode with `Set-PSReadLineKeyHandler -Key Tab -Function <mode>`
To keep it backwards compatible `GenPowerShellCompletion` will not display descriptions.
Use `GenPowerShellCompletionWithDesc` instead. Descriptions will only be displayed with
`MenuComplete` or `Complete`.
Signed-off-by: Paul Holzinger <paul.holzinger@web.de>
