Remove lift from pallet.core.operations/converge

Factor out the lift from the tail of pallet.core.operations/converge, and make
pallet.api/converge use pallet.core.operations/converge and
pallet.core.operations/lift.
Add live test for pallet.core.operations

Adds pallet.test-specs/operations-test with role :ops, which tests
p.c.o/lift and p.c.o/group-nodes, and operating on individual nodes.