fix circular dependency eo.operator<->SdbUtil
Remove some sorcer.eo.operator usage from code. Code compiles and static tests pass
ServiceContext: merge evaluation of returnValue and returnJobValue;
eo.operator: extract ExertionExecutor and Evaluator, split evaluation of Evaluation and Exertion

operator.value(Evaluation) had special handling of Exertion, which extends Evaluation, so it was safe to extract overloaded method.
remove the last circular dependency operator<->SdbUtil<->SdbOperations
move sorcer.eo.operator to own module, fix dependencies