Support check_args argument for matrix and multivariate distributions

[albertpod]

It would be nice to support the check_args argument for matrix/multivariate distributions, similarly to univariate distributions.

For Inverse-Gamma distribution we can write: InverseGamma(-1, 1, check_args=false)

While for Inverse-Wishart, Distributions.jl throws an error: InverseWishart(-2, Matrix(Diagonal(ones(2))), check_args=false)