For every struct, overload Base.show() and Base.summary()

[odunbar]

Issue

Some of the distributions and objects are very unwieldy especially when printing to terminal IO

Possible Solution

Inspiration: @glwagner at Oceananigans.jl

• Providing Base.show() methods (and improving those that currently exist) would improve the user experience in the REPL.
• Also look into Base.summary() functions which can provide something cleaner than nameof(typeof(...)) calls in error messaging etc.