Add --quiet option to suppress rpc-tests.py output

Summary:
rpt-tests.py outputs progress information as it runs tests. This commit
adds a --quiet option that suppresses that progress output and only
prints a summary of results (and logs from failed tests).

This backports core's PR9780

Test Plan:

./test/functional/test_runner.py

Reviewers: #bitcoin_abc, matiu

Reviewed By: #bitcoin_abc, matiu

Subscribers: teamcity

Differential Revision: https://reviews.bitcoinabc.org/D996