auction: `TxV/TxP` support to populate the views

[erwanor]

As of v0.75.0, there's not enough data in the current TransactionPerspectives to generate ActionDutchAuctionWithdrawViews that are useful to clients. The view exists but its content is hardcoded to have zero reserves and no positions. Instead, we should record extended metadata during scanning so that it's possible to cross-reference openings to note commitments with auction reserves. This also offers an opportunity to lay the groundwork so that we can add position views.