ignoringFieldsOnlyLhsHas for usingRecursiveComparison

[WorkProg]

Feature summary

A function that automatically ignores any fields that only the lhs has when comparing with recursiveComparision. Related to #2143, but for actual POJOs. This would basically mean, add an ignoringFields("every", "field", "lhs has", "but", "rhs has not").

Example

record A(String hello, int world){}
record B(String hello, int planet){}
record C( String hello) {}

var a = A("hello", 1);
assertThat(a).usingRecursiveComparison().ignoringFieldsOnlyLhsHas().isEqualTo(B("hello", 1)); // complain about a not having `planet`

assertThat(a).usingRecursiveComparison().ignoringFieldsOnlyLhsHas().isEqualTo(C("hello")); // this is correct (`world` is ignored)

assertThat(a).usingRecursiveComparison().ignoringFieldsOnlyLhsHas().isEqualTo(C("not hello")); // this fails because `"hello" != "not hello"`

[WorkProg]

I'd also be fine with a function that is just ignoringUnknownFields and doesn't make a difference between the lhs and rhs.