Refactor and consolidate how we explicitly check for Tor leaks in the automated test suite
In particular, distinguish between the "configured bridges" and "default bridges" cases, to make it clearer what we are actually testing in the scenarios.
When merging, please check the "Revert 5643b00e" task on #18470 (closed).
Closes: #18493 (closed)
Refs: #18470 (closed)
Edited by anonym