Make use of EntityIdTransformer

Change-Id: Ic3a0427c19c0e08a8c73344325ddbe13476a2f99
Added unhappy-path tests for EntityIdTransformer

Change-Id: I5894170d578564d69b2d5a6420e53f8ccc71549f
Created Engine component in SQLStore

Change-Id: I45f514138e4d6ba9144b96287aa254f84938731d
Remove EntityIdMap

Change-Id: I9f3f8b6536e7d31ebfca3523c1e5674d63a7d85b