Add `pelican key create` command #867

Job	Run time
set-build-parameters	4s
set-tags	6s
cache-image-layers	6m 41s
build-devtest-images	1m 0s
build-server-images (origin)	47s
build-server-images (osdf-origin)	54s
build-server-images (cache)	1m 6s
build-server-images (osdf-cache)	47s
build-server-images (registry)	1m 2s
build-server-images (director)	1m 59s
build-server-images (osdf-registry)	1m 2s
build-server-images (pelican-test)	32s
build-server-images (osdf-director)	1m 26s
test-linux-push-to-main	0s
test-linux-push-to-tag	0s
	17m 26s

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