Add new InstructionTextTokenType for HLIL inline argument names

[CouleeApps]

What is the feature you'd like to have? The tokens that are rendered in HLIL for function call argument names are simple TextTokens. They should have a new TokenType.

Is your feature request related to a problem? It is impossible to theme them given you cannot uniquely address them.

Are any alternative solutions acceptable? Could reuse another existing token type but that is kind of gross.

Additional Information: Reported by Thomas Atkins on Slack