Move reusable test code from test-jar to new test projects

Several projects create test-jar artifacts that are reused by other projects. While convenient, it does have its drawbacks and is not the preferred way.

The following artifactIds create test-jars:
accumulo.rya
mongodb.rya

Reusable code should be refactored into these new artifactIds:
rya.test.accumulo
rya.test.mongodb

Reference: https://maven.apache.org/plugins/maven-jar-plugin/examples/create-test-jar.html