Incorrect error message for invalid enumerator with enumeration namespace

[ppaulweber]

Describe the bug

The usage of invalid enumerator names of a enumeration definition does not trigger an appropriate error message that an enumerator symbol name inside a enumeration does not exist, but instead a property violation error is triggered.
The following example.casm specification was used to trigger the bug:

CASM init test

enumeration Color = { Red, Green, Blue }

rule test =
    // enumerator 'Black' is not defined inside 'Color'
    assert( Color::Black = Color::Black )

To Reproduce

The following behavior occurs with the released casmi tool with version 0.3.0 and the following command: $ casmi example.casm

$ casmi example.casm
casmi: error: argument violates 'side effect free' property, @7{5f07}
bug.casm:7:13..7:40
    assert( Color::Black = Color::Black )
            ^-------------------------^

Expected behavior

The casmi tool shall report that the enumerator Black is an unknown symbol and not defined in enumeration Color:

$ casmi example.casm
casmi: error: enumerator 'Black' is not defined in the enumeration definition 'Color'
bug.casm:7:13..7:40
    assert( Color::Black = Color::Black ) 
            ^-------------------------^

[ppaulweber]

Current status: branch created with regression test at TC, still WIP