[BUG] regression: coverlet.console missing exit codes

[Bertk]

Describe the bug

Exceptions were used instead of return values (exit codes).

0 - Success.
1 - If any test fails.
2 - Coverage percentage is below threshold.
3 - Test fails and also coverage percentage is below threshold.
101 - General exception occurred during coverlet process.
102 - Missing options or invalid arguments for coverlet