Improve live handling of TC data (quality of life).

[harrisonCassar]

Implement two (and a half) quality of life changes:

• Clean-slate TC labels (remove legacy labels).
• Handle null values from TC gracefully (when TC is not plugged in).
  • Send "-460", which is below absolute zero, to Grafana Live (for indicating dc of the TC).
• Push to Grafana Live 5x as fast.
  • Makes visualization of TC data live much nicer (continuous, not discrete).
• Flush to log file as often as possible.
  • Allows instantaneous raw viewing of log file.
  • Not too concerned about bottlenecking performance right now (can be re-decreased later).

[harrisonCassar]

This code was used to support functional test completed with Connor on the Propulsion team without issues, coupled with the new Grafana Dashboard: