Replace verifier DataType with kie-soup DataType

Idea for this code enhancement emerged during https://github.com/kiegroup/drools-wb/pull/1311/files PR review.

We have two instances of DataType, while we can replace the first one with the second one.

• https://github.com/kiegroup/drools/blob/master/drools-verifier/drools-verifier-core/src/main/java/org/drools/verifier/core/index/model/DataType.java
• https://github.com/kiegroup/kie-soup/blob/master/kie-soup-project-datamodel/kie-soup-project-datamodel-api/src/main/java/org/kie/soup/project/datamodel/oracle/DataType.java