fix(developer): quell internal error when a section fails 🙀

- when a required section is missing, only throw an internal error IF we haven't already flagged a problem.  for example, if 'vars' fails to compile because of a problem, and we already have an error on file, then don't throw an internal error that 'bksp' depends on uninitialized 'vars'.

- mimic this flow in the test helpers.

- add a test case for this in the test helpers, in test-tran

- add a strictError flag to say that no additional errs are allowed.

Fixes: #10291