FAPI TEST: rework test certificate creation #534

Job	Run time
build-test (ubuntu-18.04, gcc)	4m 15s
build-test (ubuntu-18.04, clang)	4m 56s
coverity-test	0s
test-coverage	4m 51s
scanbuild	6m 30s
build-test (ubuntu-20.04, gcc)	4m 37s
build-test (ubuntu-20.04, clang)	4m 29s
test-fuzz	2m 34s
test-mbedtls (ubuntu-20.04)	2m 58s
build-test (fedora-32, gcc)	4m 39s
test-no-crypto-build	1m 20s
build-test (fedora-32, clang)	4m 50s
test-mbedtls (ubuntu-22.04-mbedtls-3.1)	2m 48s
test-tcti-config	13m 43s
build-test (opensuse-leap, gcc)	4m 26s
build-test (opensuse-leap, clang)	4m 33s
build-test (ubuntu-22.04, gcc)	4m 26s
build-test (ubuntu-22.04, clang)	4m 44s
build-test (alpine-3.15, gcc)	3m 49s
build-test (alpine-3.15, clang)	4m 44s
	1h 29m 12s

Provide feedback