add context to errors

[agentm]

Errors from complex Project:M36 expressions are lacking in that it is often difficult to discern what components of the user's expression actually caused the error. Errors should include expression context such as related function/operator name, line number, and line offset.

To achieve this, we need the TutorialD and SQL parsers to propagate line information into the various expressions. Is there a way to achieve this out-of-band so that expressions aren't peppered with context structures? Is that even desireable?