Make random methods compatible with compilation and Opposite

[zickgraf]

Currently, random methods are not compilable because they might return fail and the compiler skips such operations as a safety measure. Additionally, the list versions cannot be installed for the opposite category because the lists might contain information about source and/or range which would have to be swapped.

Possible solutions by looking at the implementation in #1079:

1. Do not allow to return fail but simply return some default object or morphism or an error if the input integer or list is not valid.
2. Make RandomMorphismByList get three lists, one for the source, one for the range, and one for the morphism datum (and make RandomMorphismByListWithFixedSource/Range get two lists).