Implement IAlgExecStateSvc::{algExecState,addAlg}(IAlgorithm*) in terms of…
Implement IAlgExecStateSvc::{algExecState,addAlg}(IAlgorithm*) in terms of the versions taking a StringKey
- this reduces the implementation burden, as there is no other way to implement this
- this eliminates an unneccessary virtual function call when calling these methods