Fix calling rez test with empty test name to run all tests#1988

JeanChristopheMorinPerso merged 6 commits intoAcademySoftwareFoundation:mainAcademySoftwareFoundation/rez:mainfrom

Ni-g-3l:fix/run-all-tests-empty-rez-test-cmdNi-g-3l/rez:fix/run-all-tests-empty-rez-test-cmdCopy head branch name to clipboard