Extend bool_return_is_error configuration to allow including function arguments in errors

[sdroege]

For many functions it's more useful to include some of the function arguments in the string returned glib::bool_error!.

I'd suggest a syntax like bool_return_is_error = "blablabla {0} blablabla {1:?}" for this that takes the first and second argument then, the second via the Debug impl.