Show test coverage and statistics after test runs

[moodmosaic]

Current test runs don't show statistics about coverage or execution metrics.

Example output after tests complete:

Tests:      12 passed, 2 discarded
Time:       1.24s
Coverage:   86.5%

Implementation could use clarinet's coverage data and extend it with Rendezvous-specific metrics.

[moodmosaic]

Awaiting resolution of stx-labs/clarinet#1638 to proceed.