auction: credit VCB when ending an auction

[erwanor]

Describe your changes

• hotfix for auction(dutch): credit VCB when ending an auction #4388
• reproduction for auction(dutch): credit VCB when ending an auction #4388
• migration for auction(dutch): credit VCB when ending an auction #4388

Checklist before requesting a review

• If this code contains consensus-breaking changes, I have added the "consensus-breaking" label. Otherwise, I declare my belief that there are not consensus-breaking changes, for the following reason:

  This is consensus-breaking and state-breaking. Migration WIP.

[erwanor]

I have tested this in two ways:

• a local devnet running v0.75.0 with a collection of auctions running every block
• an application test that reproduce the bug (and attests that the fix works).

Additionally, I ran the migration on a fork of the running testnet to observe if any deviations were recorded, but without resuming. I didn't see any deviations, that is to say the tallied auction VCB and the one onchain were equal.

[erwanor]

This is generating conflicts to every other U1 migrations and has received a lot of offline attention so merging this optimistically, but async reviews are welcome.