Complete Overhaul of the Statistics Module

[AndreiKingsley]

Problem

Currently, the statistics code resides in a raw, unconfigured project within a private repository. Moreover, more than half of the code is a direct copy of an old version of statistics from Lets-Plot (core), without incorporating any of the fixes made in Lets-Plot. Every time we need add a new statistics we must copy-paste Lets-Plot code again. Additionally, the statistics module completely lacks tests.

Furthermore, statistics are published as a separate artifact, which frequently causes integration issues for users.

Tasks

• Align the codebase with Lets-Plot to avoid duplication and inconsistencies (simplest solution - use LP internal statistics API for implementation).
• Move the Statistics API to the main repository.
  • Possibly integrate it into kandy-lets-plot, eliminating the need for a separate artifact, as it serves no real purpose.
• Then, we can add API for remaining statistics and statistical plots (Add remaining statistics and statistical plots #369).

This also will fix #276.

[devcrocod]

Statistics should be put on github, maybe under a personal account or in a closed one in the organization
We can discuss this