snapshooter Add support for lambda expressions instead of json path for ignore and accept

When using fluent assertions, e.g. person.Should().MatchSnapshot() or the static snapshot class, e.g. Snapshot.Match(person) a generic overload now ensures that we can use lambda expressions to accept and ignore fields.

Examples:

Snapshot.Match(testPerson, snapshotName, o => o.AcceptField(p => p.Age));

testPerson.Should().MatchSnapshot(o => o
                .AcceptField(m => m.Firstname)
                .AcceptField(m => m.DateOfBirth)
                .IgnoreFields(m => m.Children['*'].Name));