* Capture error_type label on metrics/traces
* Make error messages more helpful to user
* Use errutil, categorized errors, and tie them to error_type (category in code)
* Misc trace fixes
* Add metric to track SQL input conversion
* capture errors on metrics
* rename seconds to sql_command_duration_milliseconds to match unit that has been captured, and update buckets
* rename sql_command_errors_total to sql_command_count