Get rid of commons-beanutils

[vkochnev]

Spring Cloud Contract uses commons-beanutils which is extremely old and depends on even more outdated and moreover vulnerable commons-collections library, there is also no evidence that common-beanutils will be updated any time soon.

The use of the aforementioned library is quite limited and should be easy to rewrite without use of this library.
I actually found only one usage:

spring-cloud-contract/spring-cloud-contract-verifier/src/main/java/org/springframework/cloud/contract/verifier/builder/JsonBodyVerificationBuilder.java

Line 303 in d771b76

Object result = new PropertyUtilsBean().getProperty(templateModel, justEntry);

Also there are several usages of commons-collections in one file:

spring-cloud-contract/spring-cloud-contract-verifier/src/main/java/org/springframework/cloud/contract/verifier/converter/YamlToContracts.java

Line 43 in d771b76

import org.apache.commons.collections.MapUtils;

Which can be replaced with Spring specific implementations or commons-collections4 if it's not possible.