Remove the MVEL dependency from kie-internal

The kie-internal module has a dependency on MVEL. This jira is for the task of removing that dependency from kie-internal.

The problem is that the MVEL dependency (org.mvel:mvel2) is nearly 1MB large!

This means that the dependency tree grows by 1MB everywhere where kie-internal is used, among others: kie-remote-client, which has the explicit goal of being as small a dependency as possible, given that it's meant to be used as a lightweight client jar.