Code Formatting: general variable name conventions

[nimrod46]

We need to define first what every significant value name should be.

1. "Breathing cycle", I don't like this name as someone reading the code could be confused with the other meaning of the word breath. So I suggest respiration_cycle.
2. "loop cycle" using cycle again does not seem right as someone who is less familiar with this software or in general with how code works will most likely think it's about the respiration cycle (it can be confusing for everyone actually as point 1 and 2 have quite a lot of variables, confused me too).
   I suggest using update, update_time, update_lost, time_since_last_update, etc' just not mentioning the word cycle.
3. "index", used to describe the current step in the "motion profile" profile, so I suggest using respiration_step, maybe respiration_step_index because it's used as an index after all.

@ElectricRCAircraftGuy tell me what you think on those points, there are more general variables to add here as well I guess.