swap: TxDescriptor<{
    id: number;
    other: number;
}>

Swap a lease holding parachain with another parachain, either on-demand or lease holding.

The origin must be Root, the para owner, or the para itself.

The swap will happen only if there is already an opposite swap pending. If there is not, the swap will be stored in the pending swaps map, ready for a later confirmatory swap.

The ParaIds remain mapped to the same head data and code so external code can rely on ParaId to be a long-term identifier of a notional "parachain". However, their scheduling info (i.e. whether they're an on-demand parachain or lease holding parachain), auction information and the auction deposit are switched.