Pattern Miner considering too many groundings

[Nil Geisweiller]

MinerUtils::restricted_satisfying_set should only check whether the given text matches or not, rather than considering subhypergraphs, as well as permutations due to unordered links, which is contrary to how empirical probability is calculated.

[Linas Vepštas]

permutations over unordered links are needed only if there are two or more ungrounded variables. Otherwise, one can promptly make a 1-to-1 match; permutations are not needed for this