Add noise exposure/dose calculations

[elliotmatson]

It would be helpful to have a meter for 24hr noise dose for live events. In the US there are different parameters from NIOSH and from OSHA, and it looks like Europe has their own as well

This is the calculation detailed by OSHA:
https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.95AppA

Here's an exposure calculator that lists even more standards, and their calculation parameters:
https://www.noisemeters.com/apps/exposure-calculator/

I can potentially work on a PR, most of my c/c++ experience is in the embedded world though

[psmokotnin]

Interesting one, I'll take a look