pairings-signatures-library: Create the method that signs a byte array

[poulok]

Following: https://github.com/hashgraph/hedera-services/blob/develop/platform-sdk/docs/proposals/TSS-Library/TSS-Library.md
Section: #Hedera Cryptography Pairings Signatures Library
Implement the Signature class and possibility of signing a byte array message using a private key

• sign a message: It is the scalar multiplication of the private key element, and the hashToGroup GroupElement from the message, of the Group configured in the SignatureSchema for signatures.
• serialization of the signature.

The creation of the signature should be responsibility of the private key class
The serialization of the signature is responsibility of the signature class.

Note on serialization, it should be produced with ByteString class of protobuf. The first byte should include the serialized form of the SignatureSchema

Depends on:
#14788
#14786