Function invite_user_handler 

async fn invite_user_handler(
    __arg0: State<ServerState>,
    __arg1: AuthenticatedClientRequest<Request>,
) -> Result<ArminiusResponse<Response>, InviteUserError>

Handler for POST /_matrix/client/v3/rooms/{roomId}/invite (See https://spec.matrix.org/v1.15/client-server-api/#thirdparty_post_matrixclientv3roomsroomidinvite).

This endpoint is used to invite an user to a room.