Check automatic variable availability

In comparing the Preference Variables documentation for PowerShell 6.x and newer:
https://docs.microsoft.com/en-us/powershell/module/microsoft.powershell.core/about/about_preference_variables?view=powershell-6

to the Preference Variables documentation for PowerShell 5.1:
https://docs.microsoft.com/en-us/powershell/module/microsoft.powershell.core/about/about_preference_variables?view=powershell-5.1

it seems that a number of Preference Variables were removed/deprecated from PowerShell. I just ran into this problem unexpectedly on a script when testing it on PowerShell 6.x.

To help with this problem, I would like the PSUseCompatibleCommands feature of PSScriptAnalyzer to flag the usage of deprecated Preference Variables and state that they are not compatible with PowerShell 6.0 and newer (on any platform including Windows).

Inizia confrontando la documentazione collegata di about_Preference_Variables per PowerShell 6.x e 5.1, quindi individua la funzionalità PSUseCompatibleCommands in PSScriptAnalyzer. Il lavoro è completato quando l'uso di variabili di preferenza obsolete viene segnalato con l'indicazione che è incompatibile con PowerShell 6.0 e versioni successive su tutte le piattaforme.