[CI] Make the coverage report available to Teamcity

Summary:
This diff creates an archive from the coverage directory that has the
expected format for Teamcity. This should appear as an HTML page in the
build report tab.

Depends on D6607.

Test Plan:
Run the CI build-coverage build plan and check the report tab has the
coverage report.

Reviewers: #bitcoin_abc, deadalnix

Reviewed By: #bitcoin_abc, deadalnix

Subscribers: deadalnix

Differential Revision: https://reviews.bitcoinabc.org/D6608