Add partiality/delay monad #573

Job	Run time
initialise	6s
quick-check	6m 24s
windows-bootstrap-chez	24m 5s
ubuntu-bootstrap-chez	7m 43s
nix-bootstrap-chez	21m 12s
ubuntu-bootstrap-racket	12m 56s
macos-bootstrap-chez	17m 53s
ubuntu-self-host-previous-version	11m 18s
ubuntu-self-host-chez	10m 43s
ubuntu-build-api	4m 1s
ub-test-elab-util	42s
ub-test-collie	32s
ub-pack-test-lsp	13m 57s
ub-pack-test-pack	11m 45s
ub-test-frex	1m 26s
ub-test-katla-and-html	6m 0s
ubuntu-self-host-racket	0s
macos-self-host-chez	45m 15s
windows-self-host-racket	13m 9s
	3h 29m 7s

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