add rule_result_f function that returns ruleresesult

[chris-twiner]

although types must be known up front if there is an expression ruleresult this pair can be forced into a lambda with the correct dymanic type and return a ruleresult.

Sample usage is expressionRunner(aggExpr) then rule_result_f(er, ids... , r -> r.full.field.available > 0)

[chris-twiner]

should return a null if the deserialisation can't be managed given it's no longer static, exceptions get logged etc.

[chris-twiner]

Not possible given types needed for lambda