Improve cache hit rate

[jwanner83]

Instead of matching only exact matches:

cached: [2,1,3] = [1,2,3]

input: [2,1,3] // <- hit
input: [3,2,1] // <- no hit, even though the sorted array would look the same

we could match all inputs which contain all numbers of an already cached entry:

cached: [2,1,3] = [1,2,3]

input: [2,1,3] // <- hit
input: [3,2,1] // <- hit

this would improve the cache hit rate by a lot and would prevent the database to be flooded by entries with the same result.