Renames & implementation for timing.c adc.c

[nathhandup]

• Renamed files from time -> timing for readability
• changed one functions return value to be a boolean to account for potential failure to grab processor clock time
• implemented both adc and timing.c

[nathhandup]

some things im considering:

• checking for exceeding reverse phase currents
• checking for some sort of undertemperature?

[leogmendoza]

adc is mostly good, i just need you to cut some more out of timing

[nathhandup]

Made the requested changes, also renamed files back to time.c and time.h since theres no longer a name conflict without time.h.

Still confused about the listed return parameters for the adc.h functions, where it says "True if the measurement is valid, false otherwise". I removed the checks anyways, but are there other checks we should be making?