Fixes for gggenomes visualization scripts

[lcoombe]

• Fix sorting order for ribbon plots
  • With some file names and orders, the assemblies were plotted out of order, which lead to ribbons being missing erroneously
• Fix for input FAI files for the gggenomes prep scripts being in directories other than the current working directory
  • Previously, was assumed there was no path specified, but with fix, the FAI files can be located anywhere