Add new rule to catch syntax error e.g. "elif" instead of "elseif"

Summary of the new feature

Try formulating it in user story style (if applicable):
'As a python and powershell developer I want ScriptAnalyzer to detect when I use elif (python) instead of elseif (powershell) so that the ci warns me about invalid statements and I can correct the code.'

Proposed technical implementation details (optional)

For powershell modules we need an additional ci check. Currently syntax errors are not always covered. The ci for example does currently not cover usage of elif instead of elseif (former is python later is powershell).

Example shippables: https://app.shippable.com/github/ansible/ansible/runs/133592/1/console (source)
It erroneously reports unused variables instead of a syntax error.

What is the latest version of PSScriptAnalyzer at the point of writing

Inizia esaminando i controlli CI del modulo PowerShell e riproduci il caso segnalato usando elif dove PowerShell si aspetta elseif. Confronta la diagnostica risultante con la segnalazione di errore di sintassi prevista; il lavoro è completato quando questo uso improprio viene rilevato da CI invece di essere segnalato soltanto come variabili inutilizzate.