Mismatch between specs and implementation around NewTaskEncryptionKey

[lacabra]

Describe the bug
As per https://github.com/enigmampc/enigma-p2p/blob/elichai-patch-2/docs/IPC_MESSAGES.md#newtaskencryptionkey-message, the incoming message should contain userPubKey, yet the current implementation in:

• https://github.com/enigmampc/enigma-core-internal/blob/6b2d64a3e9377b2004b00d4084d0e80530cf58a1/enigma-core/app/src/networking/messages.rs#L46
• https://github.com/enigmampc/enigma-core-internal/blob/3e9a21224bdb366507461b0a91e6a5828692faae/enigma-core/app/src/networking/ipc_listener.rs#L50

are configured to expect pubkey.

ToDo
Adjust the code to match the specs.