prepare Message
suspend fun Conversation.prepareMessage(encoded: EncodedContent, options: SendOptions? = null): MessageId
suspend fun <T : Any> Group.prepareMessage(codec: ContentCodec<T>, value: T, options: SendOptions? = null): MessageId
suspend fun <T : Any> Dm.prepareMessage(codec: ContentCodec<T>, value: T, options: SendOptions? = null): MessageId
suspend fun <T : Any> Conversation.prepareMessage(codec: ContentCodec<T>, value: T, options: SendOptions? = null): MessageId