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

首先检查 PowerShell 模块的 CI 检查，并在 PowerShell 期望 elseif 的位置使用 elif，重现报告的情况。将生成的诊断结果与预期的语法错误报告进行比较；当 CI 检测到这种误用，而不是仅将其报告为未使用的变量时，即表示完成。