- Split 69 functional tests into 4 groups for parallel execution
- Add check-functional-parallel target to Makefile.am
- Fix VPATH builds with $(srcdir)/tests path
- Add test failure detection verification in CI
- Update Dockerfiles with parallel make -j$(nproc)
- Add --depth 1 for faster git clone in Dockerfiles
## Summary
Fixes https://github.com/profanity-im/profanity/issues/1907
Update functional and unit test code to comply with the current cmocka test runner.
## Changes
- `UnitTest` struct to `CMUnitTest` struct
- `unit_test()` macro to `cmocka_unit_test(f)` macro
- `unit_test_setup_teardown()` macro to `cmocka_unit_test_setup_teardown` macro
- `run_tests()` macro to `cmocka_run_group_tests()` function
- Setup and teardown functions return `int` instead of `void`
## Testing
### Unit Tests
`make check`
### Functional Tests
I did not compile or run functional tests because they are *shelved* for now.
### Valgrind
I'm not entirely sure how to fun Valgrind in this case. I did not do fancy memory management, so it should be fine.
