Introduce PathValidator.

[christophstrobl]

Introduce a dedicated validator that can verify and potentially reject a given dot path against the potential navigable paths of an aggregate.

PathValidationRules rules = PathValidationRules.builder()
	.denyAccessTo("**.password")
	.maxSegmentLength(32)
	.build();

PathValidator.validate(User.class, "account.password", rules); // -> PathResolutionException

Simplify Sort validation by checking Order instances against a given ruleset

Sort sort = ...

Sort.validate(Person.class, sort); // predefined ruleset

Sort.validate(User.class, sort, rules -> { // custom rules
	rules.denyAccess("**.password");
});

Closes: #1365