Add clarity to key names

[gkc]

Describe the bug
Not clear from looking at key names in the keys file or when being used, what format those keys are in

Expected behavior
Better code comments explaining why the key names in the keys file are called what they are

Better names for the in-memory key map entries once they have been loaded from file and decrypted / processed as required

Additional context
From @realvarx

Can I treat "aesPkamPrivateKey" as a RSA private key? Or is it encrypted in other way?

Reply from @gkc

Hmmm I think the reason it’s called that in the keys file is because it is an RSA private key but it is AES-encrypted using the selfEncryptionKey