Extend the list of Physical constants defined in AtomicAndPhysicalConstants

[DavidSagan]

The repo https://github.com/LaGuer/PhysicalConstant.jl has a list of physical constants, some of which could be considered. Note: The names of constants should be discussed. As a practical matter, using a name like c for speed of light can be confusing in code where someone might not realize that c is a physical constant as opposed to a local variable.