* implement multivariate psrf

* implement multivariate gweke diagnostics

* use matrices as input variable and implement R wrapper

* request export in R

* improve mc diagnostics

* initial implmentation of raftery diagnostics

* implement empquant subroutine for raftery diagnostic

* implement thin subroutine for raftery diagnostic

* implement mctest subroutine for raftery diagnostic

* implement mctest subroutine for raftery diagnostic

* implement indtest subroutine for raftery diagnostic

* implement ppnd subroutine for raftery diagnostic

* export to R function raftery and fix compiler errors

* complete raftery implmentation

* remove unused samples and add roxygen comments

* update mcmc diagnostics code and comments

* remove unused comments and update roxygen comments

* fix bugs in billiard and mcmc diagnostics

* improve comments and raftery marginal diagnostic

* add mcmc diagnostics test

* improve raftery implmenation. Add comments to describe mcmc diagnostics

* update roxygen comments and variable names in mcmc diagnostics

* improve raftery diagnostic

* optimizations in prsf and geweke diagnostics, fix params warning in geweke Rcpp function

* fix c++ tests and improve raftery diagnostic

Co-authored-by: Tolis <tolis.chal@gmail.com>