Inconsistent on static analysis and design guideline

## Description
Our design guideline states that there should be <= 4 positional parameters
https://github.com/Azure/azure-powershell/blob/master/documentation/development-docs/design-guidelines/parameter-best-practices.md#positional-parameters-limit
but in the static analysis, we check if there's a parameter with position >=4
https://github.com/Azure/azure-powershell/blob/master/tools/StaticAnalysis/SignatureVerifier/SignatureVerifier.cs#L276

This is inconsistent, for example when a param has position=4.
Also when there are <= 4 params but the actual position number is >4.

## Conclusion
Need to update static analysis tool to actually detect if have <= 4 positional parameters.

## Cost

Read the positional-parameter limit in documentation/development-docs/design-guidelines/parameter-best-practices.md and inspect the check near line 276 of tools/StaticAnalysis/SignatureVerifier/SignatureVerifier.cs. Verify how the static analysis handles a parameter at position 4 and cases with four or fewer parameters whose position numbers exceed 4. Done means the analysis matches the documented limit.

Written by the indexing model from the issue text.