Add distributions handling to CDF(), Mean(), Variance(), PDF() functions

[Axel Kramer]

Add handling for: BernoulliDistribution, BinomialDistribution, HypergeometricDistribution, NormalDistribution, PoissonDistribution, etc in symbolic and numeric mode:

Add new distribution names to:

org.matheclipse.core.convert.AST2Expr#FUNCTION_STRINGS

See prepared function templates:

• CDF()
• Mean()
• PDF()
• Variance()

[Axel Kramer]

Please use the Github issue tracker to open a new issue if this issue shouldn't be closed Github issues