chainparams: add allowed assumeutxo values

Summary:
Values for mainnet and testnet will be specified in a follow-up PR that can be
scrutinized accordingly. This structure is required for use in snapshot activation
logic.

This is a backport of core#19806 [4/8] and core#21584 [2 & 3/5]
https://github.com/bitcoin/bitcoin/pull/19806/commits/7a6c46b37edb8bfa0085d202aa7e9427d5e4fceb
https://github.com/bitcoin/bitcoin/pull/21584/commits/00000077098a23e0ac9781f5f799c90fd2fd97de
https://github.com/bitcoin/bitcoin/pull/21584/commits/fa5668bfb34e2778936af30e9fb6bd3c6bcf41fd (partial)

Notes:

• The new circular dependency was added by core in a later commit. We already need it here.
• We also check the allowed hashes in a functional test reproducing the deterministic regtest chain and allowed hashes.

Depends on D11328

Test Plan: ninja all check-all

Reviewers: #bitcoin_abc, Fabien

Reviewed By: #bitcoin_abc, Fabien

Subscribers: Fabien

Differential Revision: https://reviews.bitcoinabc.org/D11238