feat: add verify to message-encryption

[vpavlin]

This is a feature or change request

Problem

When I implemented https://github.com/vpavlin/qaku, I used some random crypto wrapper instead of @waku/message-encryption package as it lacked verify() method (I could have probably just called the implemenation in noble-secp256k1 directly, but haven't realized it then).

Proposed Solutions

Since @waku/message-encryption contains sign() method (i.e. people will use it to sign messages), it should also expose verify() to verify validity of the message and signature.

Notes