Refactor TEDAPI Vitals for Readability

[mccahan]

This is the most-easily-separable part of #153 - just pulling the vitals function out into a separate file.

Testing

• Run this branch alongside an existing version
• Open /vitals in each, and compare side-by-side
  • I did this using a diff tool, and noted that the only difference between the two would be small measurement differences based on the timing of the data pull

N.B. I only have a PW3 to test on, none of the Neurio stuff, so I can't test those parts (though they should be essentially unchanged)

[jasonacox]

We need to move the METER_Z (TEMSA block) code into vitals.py.