streamline LHCb::Algorithm namespace

• factor out default traits into a single location
• import usesConditions and usesBaseAndConditions into the Traits namespace
• migrate the algorithms in LHCbAlgs to use the LHCb::Algorithm namespace (and thus implicitly from GaudiAlgorithm to Gaudi::Algorithm)

use the above in UnpackRawEvent, MaterialBudgetAlg and DeFTTestAlg to verify the changes