IllegalAnnotationInspection attempts a case-sensitive enum parse

[retailcoder]

https://github.com/rubberduck-vba/Rubberduck/blob/next/Rubberduck.Inspections/Concrete/IllegalAnnotationInspection.cs#L162

That's a problem. It causes an ArgumentException to be thrown when a '@folder annotation is encountered - but annotations shouldn't be case-sensitive.

[comintern]

Duplicate of #3907.