topdown: Use sorted list from rule tree
topdown: Use sorted list from rule tree

This commit updates the evaluator to use the sorted list of rules
added in the previous commit. This way the evalTree phase enumerates
and evaluates the full extent of virtual documents in the same order
across runs.

Signed-off-by: Torin Sandall <933af5bec0bc58056526d55ca6c7b45fcf14cc48@gmail.com>

tsandall/opa,tsandall/opa,open-policy-agent/opa,open-policy-agent/opa,open-policy-agent/opa,open-policy-agent/opa,open-policy-agent/opa,tsandall/opa,tsandall/opa,tsandall/opa,tsandall/opa,open-policy-agent/opa