SYSML21 — Alias definition in GBNF is misaligned with textual and abstract syntax

For "historic" reasons the GBNF included an option to specify an alias as part of definition or usage nodes within the name compartments. This is completely misaligned with the textual notation where alias specification is separate from specification of definitions/usages. The alias expression should be removed from the Definition/Usage name compartments.
It is currently found in the non-terminals 'usage-name-with-alias' and 'definition-name-with-alias'.
Instead, an alias may be specified using a specific "alias node", that maps to an alias definition, similar to what is described in clause 7.