Function decryptGroupMessage

decryptGroupMessage(
    event: NostrEvent,
    clientState: ClientState,
    ciphersuite: CiphersuiteImpl,
): Promise<GroupMessagePair>
Decrypts a kind 445 event and returns the MlsMessage it contains.
Parameters
- event: NostrEvent
  The Nostr event containing the encrypted MLS message
- clientState: ClientState
  The ClientState for the group (to get exporter_secret)
- ciphersuite: CiphersuiteImpl
  The ciphersuite implementation
Returns Promise<GroupMessagePair>
The event and the decoded MlsMessage
- Defined in ../home/robert/Projects/marmot-ts/src/core/group-message.ts:132