CaloTowerxAODAlgoBase migrated to retrieving Calo DD manager from the Condition Store

In the old implementation, CaloTowerxAODAlgoBase used Calo DD manager at initialization for building an index cache. The mechanism of building the cache did not seem to be sensitive to Calo alignment changes. Hence, the simplest migration was to keep the cache inside CaloTowerxAODAlgoBase, but turn it into a CxxUtils::CachedValue with lazy initialization from execute().

The new implementation is expected to produce the same results as the old one (which had not been listening to alignment callbacks anyway). However, if it gets determined that the index cache building is indeed sensitive to alignment changes, then the cache must be turned into a condition object (can be done in later MR-s, if needed).