Parse all different values for bool? parameters

[daniel-lerch]

Currently, as of 5.7.13, ConsoleAppFramework treats bool? parameters as a switch just like bool parameters. That means if the switch is present the value of the parameter will be true, otherwise its default value (null). I would prefer to be able to use all different values:

Variant A:

Input	parameter
app --parameter true	true
app --parameter false	false
app	null

Variant B:

Input	parameter
app --parameter	true
app --no-parameter	false
app	null