[jboss-jira] [JBoss JIRA] (DROOLS-5490) Implement built-in functions scheleton management

Implement built-in functions scheleton management ------------------------------------------------- Key: DROOLS-5490 URL: https://issues.redhat.com/browse/DROOLS-5490 Project: Drools Issue Type: Feature Request Reporter: Gabriele Cardosi Assignee: Gabriele Cardosi Priority: Major Labels: TrustyAI Implement common flow for [built-inf functions|http://dmg.org/pmml/v4-4-1/BuiltinFunctions.html]. Implement * [if|http://dmg.org/pmml/v4-4-1/BuiltinFunctions.html#boolean6] * [uppercase|http://dmg.org/pmml/v4-4-1/BuiltinFunctions.html#uppercase] * [lowercase|http://dmg.org/pmml/v4-4-1/BuiltinFunctions.html#lowercase] as example