Add tests for rnp_revocation_signature_create() and related functions. #3353

Job	Run time
cmake-offline-googletest	4m 13s
cmake-offline-googletest-src	4m 11s
system-sexpp, sexpp shared libs on, rnp shared libs on	2m 46s
package-source	33s
system-sexpp, sexpp shared libs on, rnp shared libs off	2m 51s
ubuntu-latest [CC gcc; botan; shared libs on; GnuPG stable]	4m 11s
system-sexpp, sexpp shared libs off, rnp shared libs on	3m 0s
ubuntu-latest [CC clang; botan; shared libs on; GnuPG stable]	4m 11s
system-sexpp, sexpp shared libs off, rnp shared libs off	3m 2s
ubuntu-latest [CC gcc; openssl; shared libs on; GnuPG stable]	4m 26s
ubuntu-latest [CC clang; openssl; shared libs on; GnuPG stable]	4m 12s
ubuntu-20.04 [CC gcc; openssl; shared libs on; GnuPG stable]	3m 40s
ubuntu-latest [CC gcc; botan; shared libs off; GnuPG stable]	4m 5s
package	53s
debian-tests	12s
	46m 26s

Provide feedback