Heatmap refactoring, fixes, and new coloring method

[jstone-dev]

• Refactored ScoreSetHeatmap to simplify data preparation and make it more readable.
• Fixed some TypeScript problems.
• Addressed a problem preventing switching between protein and DNA heatmaps.
• Fixed two issues affecting some experiments using endogenous editing:
  • No heatmap was shown when the investigator's hgvs_nt strings were genomic.
  • When the investigator provided both hgvs_nt and hgvs_pro in endogenously-edited library experiment data, we were using our own translated hgvs_pro in the protein heatmap.
• Changed the heatmap palette and replaced the functional-class-sensitive coloring mechanism with one based only on the score range and baseline score, if any.