Restructure the egamma specific code for caloExtensions
Restracture the egamma specific code for caloExtensions
- Move the code specific to the calo layers egamma needs from the ParticleCaloExtensionTool to the EMExtrapolation Tool
- Factor out in an additional method in the ParticleCaloExtensionTool the the Layers to Surfaces step.
- Migrate the egamma clients, now we can create the target surfaces from the cluster's layers once and re-use them