TrkEventCnvTools+InDetEventTPCnv+StoreGate: Fix use of ReadHandle.
Create ReadHandle from ReadHandleKey. Otherwise, we get the non-reentrant behavior of ReadHandle, which binds and unbinds from the proxy, leading to a hotspot in unbindProxy().
Create ReadHandle from ReadHandleKey. Otherwise, we get the non-reentrant behavior of ReadHandle, which binds and unbinds from the proxy, leading to a hotspot in unbindProxy().