feat: support application subnets for PocketIC (#159) #578

Job	Run time
test-extension (macos-12, nns)	9m 24s
test-extension (macos-12, nns, pocketic)	12m 7s
test-extension (macos-12, sns)	12m 52s
test-extension (macos-12, sns, pocketic)	11m 55s
test-extension (ubuntu-20.04, nns)	7m 57s
test-extension (ubuntu-20.04, nns, pocketic)	10m 16s
test-extension (ubuntu-20.04, sns)	9m 48s
test-extension (ubuntu-20.04, sns, pocketic)	9m 38s
e2e:required	1s
	1h 23m 58s

Provide feedback