Add fph meta map

[renzibei]

Hello, I add the fph::MetaFphMap from https://github.com/renzibei/fph-table. This map is similar to the fph::DynamicFphMap, but it uses metadata. So it is faster in find when success rate is 0% and the elements number is large. This can be observed from the existing RandomFind_500000 test.