Incorrect chromosome naming in the ChIP-seq tutorial

The tutorial has BAM/BED files with `X` instead of `chrX`. This apparently causes issues with visualizing on IGV (maybe older versions). Replacing `X` with `chrX` in all files should fix any issues with incompatibilities.

https://github.com/galaxyproject/training-material/tree/main/topics/epigenetics/tutorials/formation_of_super-structures_on_xi