Add caching to various parts of the bar to reduce the amount of CPU required on a per-frame basis.

Bar text is still a major source of CPU usage for the bar. By the very nature of having Boolean logic checks, large parts of the bar text need to be reparsed on every refresh. Try to add caching to this to reduce how much needs to be searched through for each branch of the logic tree.

This helps to unblock #152 from becoming a reality.

• Bar Text
• Colors
• Thresholds
• Bar values

90% reduction in CPU for bar text, ~50% overall for Shadow Full Advanced as a benchmark. Closing this but may reference it again if I make further adjustments.