internalise EncryptionService

renamed to RijndaelEncryptionService
move over to constructor injection for RijndaelEncryptionService
move encryption to be a feature
better encryption construction
make encryption a feature
EncryptionMutator needs to be InstancePerCall

since it has an instance based visitedMembers
Make EncryptionFeature EnableByDefault
remove ConfigureRijndaelEncryptionServiceTests

they no longer make sense
add extra test for RijndaelEncryptionService
Merge pull request #2270 from Particular/encryptionRefactor

Converted RijndaelEncryptionService to be a ConfigurationBuilder exension