Tracing and debugging

[justinmchase]

• Trace data needs to be optionally emitted during compilation
• It should trace the full path and match results of every pattern throughout the entire operation
• It should be possible for a tool to render the trace in a matter which a user could consume at a high level of what happened as well as to step through the parse and see what happened one step at a time.
• Which pattern operation, rule name, grow operation and path location needs to be stored in the trace

Tools

• The CLI should allow trace data to be emitted
• The Deploy should allow trace data to be emitted
• The VSCode extension should support displaying trace results, ala regexr UI.

Not yet in-scope

Supporting step by step debugging seems like a stretch for now. Its obviously desirable but I think some further research would be needed to know how to implement it.