Feature/3165 recursive comparison assert

[amodolo]

Check List:

• Fixes RecursiveComparisonAssert: improvement for comparing field with different types in actual and expected objects. #3165
• Unit tests : YES
• Javadoc with a code example (on API only) : YES

Add RecursiveComparisonAssert.withEqualsForTypes and RecursiveComparisonAssert.withComparatorForTypes methods to compare different type objects in a type-safe way. For the latter, I've added a BiComparator functional interface to avoid the declaration of a Comparator<Object> that requires a forced cast of the instances to be compared.

Furthermore, to fix the type clash generated by this kind of registration

assertThat(actual).usingRecursiveComparison()
                  .withComparatorForTypes(comparator1, String.class, LocalTime.class)
                  .withComparatorForTypes(comparator2, String.class, LocalDate.class)

I've modified the internal TypeHolder data structure from
protected final Map<Class<?>, T> typeHolder;
to
protected final Map<Pair<Class<?>, Class<?>>, T> typeHolder;
This allows us to associate a Comparator to a type's pair ([String, LocalTime] -> comparator1).

Retro compatibility is maintained; in the following scenario

assertThat(actual).usingRecursiveComparison()
                  .withComparatorForType(comparator1, String.class)

The typeHolder will contain this entry ([String, null] -> comparator1).

The only method that has changed the signature is TypeHolder.entityByTypes from
public Stream<Entry<Class<?>, T> entityByTypes()
to
public Stream<Entry<Pair<Class<?>, Class<?>>, T>> entityByTypes()
that's why this cannot be considered as a safe change...let's talk about this

[joel-costigliola]

Thanks @amodolo, I will review your PR in the next few weeks.

[joel-costigliola]

@amodolo thanks for the good quality of the code, I have finished the first round of reviews mostly on the production code, I have some questions that can impact the PR quite a bit, so I prefer we tackle them before I continue on the review since this could change the PR significantly.