* enh(tests): new tests on external-commands (rgres@centreon.com, jcroques@centreon.com)
* circular_buffer rewritten (jcroques@centreon.com)
* external command factorization (jcroques@centreon.com)
* broker uses precompilated headers (jcroques@centreon.com)
* engine/test directory removed.
* sonar issues fixed (jcroques@centreon.com)


REFS: MON-12158

Co-authored-by: rem31 <73845199+rem31@users.noreply.github.com>