Reimplement methods from kotlin-statistics

[altavir]

Port/re-implement methods from https://github.com/thomasnield/kotlin-statistics. Use stream-based reduction and Buffer.

The API is here: https://github.com/mipt-npm/kmath/blob/dev/kmath-stat/src/commonMain/kotlin/space/kscience/kmath/stat/Statistic.kt

Example usage is here: https://github.com/mipt-npm/kmath/blob/dev/kmath-stat/src/jvmTest/kotlin/space/kscience/kmath/stat/StatisticTest.kt

One needs to implement a Statistic class/object for each quantity from kotlin-statisitcs. If the reduction could be done in parallel, one should use ComposableStatistic instead.

Use Mean and Median as a reference.

[d-lowl]

Just fyi, I have made a start on this issue today (porting geomean first) -- https://github.com/d-lowl/kmath/tree/port-statistics
I'll see how much I can squeeze out this weekend.

[altavir]

I am very happy to hear that. Please do not hesitate to write if you think that there should be some changes in the statistic API. I made it this way so we could do non-blocking streaming processing of large data. But it is not much tested yet.