create_pool: TxDescriptor<{
    asset1: {
        interior: XcmV3Junctions;
        parents: number;
    };
    asset2: {
        interior: XcmV3Junctions;
        parents: number;
    };
}>

Creates an empty liquidity pool and an associated new lp_token asset (the id of which is returned in the Event::PoolCreated event).

Once a pool is created, someone may [Pallet::add_liquidity] to it.