Proposal: member functions in Enums

At this moment, the following is not allowed:

```
Public Enum MyEnum
Value1
Value2
Value3

Public Function MyEnumFunction As String
Return "My Enum Function"
End Function
End Enum
```

But I can do the following:
```
Public Enum MyEnum
Value1
Value2
Value3
End Enum

Public Module ExtendEnum
_
Public Function MyEnumFunction(myEnum as MyEnum) As String
Return "My Enum Function"
End Function
End Module
```

Which gives the same result.
But I'd rather use the first one than misuse extensions.