RHBA-626 Tree model does not work on models expecting numeric output (#1847) (#1852) * Updated the process that generates the Java classes to now include a TreeNode so that the node's outcome is of the type needed * Updated the AbstractModel so that retrieving the mining fields does not exclude any fields * Added a method to the Treemodel to return the source for a TreeNode java class * Added context to the name of the generated TreeNode objects, in the templates that use TreeNode * Created an mvel template to be used in generating the TreeNode java class