[test] Reduce Transient Simulation and Regression Failures

These tests are non-deterministic and the expected range for swap output amounts is a bit too sensitive. The main thing we want to ensure with these is that outbounds are properly broadcast to the mocknet daemons, so this relaxes the amount requirements slightly.

EDIT: amended with one more tweak to automatically retry regression tests that fail on a timeout - should have done this long ago, should drastically reduce need for manual retries which have been more frequent recently.