Capture stacktrace on SameThreadVerifier creation

If `SameThreadVerifier` is enabled we can capture stack trace where this object was created and then print it on assertion error (or add it as a cause). It should help with debugging such errors.

Start at the SameThreadVerifier implementation and trace where it is created and where assertion errors are produced. Capture the creation stack trace, then verify that a resulting assertion error displays it or includes it as a cause; the issue does not name specific files or tests.

Written by the indexing model from the issue text.