Incorrect number of parameters is not detected if function name differs in case

[StephenWeatherford]

Checking for unrecognized functions doesn't care about case:

But checking for number of args does:

EXPECTED: According to https://docs.microsoft.com/en-us/azure/azure-resource-manager/resource-group-template-functions:
Template functions and their parameters are case-insensitive. For example, Resource Manager resolves variables('var1') and VARIABLES('VAR1') as the same. When evaluated, unless the function expressly modifies case (such as toUpper or toLower), the function preserves the case. Certain resource types may have case requirements irrespective of how functions are evaluated.