Add irma cmd option to prolong keys #624

Job	Run time
test	7m 24s
docker-build	59s
lint	1m 42s
build (linux, amd64)	1m 5s
build (linux, 386)	55s
build (linux, arm)	1m 6s
build (linux, arm64)	57s
build (darwin, amd64)	1m 0s
build (darwin, arm64)	1m 7s
build (windows, amd64)	1m 3s
build (windows, 386)	1m 9s
build (windows, arm)	51s
build (windows, arm64)	57s
analyze	3m 12s
integration-test-clientside (v0.13.2)	2m 57s
integration-test-serverside (f0023141ec429d912e329665f937d05b178a3fee)	3m 30s
	29m 54s

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