More dramatic syntax error warning for sched rule

[bashbash]

srschaff https://jira.jpl.nasa.gov/browse/AERIEQS-385 Low when copy/pasting very long scheduling rules (eg from their permanent storage in a git repo), it is very easy to miss the tiny red underline and sidebar highlight for eg a missing final "}" on the whole block.

suggest popping up a warning when pressing the save button on a goal with a warning. (but should probably still allow saving invalid goals nonetheless!)