Run all extended tests on master for build-default

Summary:
We should not be skipping tests while running on master.
Preliminary tests indicate we can run all extended tests without a
significant hit to performance with some tweaking of the number of
threads while running test_runner. In the mean time, build-default
only runs an additional 10 minutes which doesn't drastically affect
our dev process anyway.

Test Plan: ./build-configurations.sh

Reviewers: #bitcoin_abc, deadalnix, Fabien

Reviewed By: #bitcoin_abc, Fabien

Differential Revision: https://reviews.bitcoinabc.org/D4371