refactor, consensus: remove calls to global `Params()` in validation layer #23448

This PR removes calls to global Params() in validation layer (except in the CChainState constructor).

Motivation: Reducing the use of global variables makes code more predictable.

Requires #23437 as it changes the visibility of CChainState::m_params to public.

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Conflicts

Reviewers, this pull request conflicts with the following ones:

• #23581 (Move BlockManager to node/blockstorage by MarcoFalke)
• #23174 (validation: have LoadBlockIndex account for snapshot use by jamesob)
• #22674 (validation: mempool validation and submission for packages of 1 child + parents by glozow)

If you consider this pull request important, please also help to review the conflicting pull requests. Ideally, start with the one that should be merged first.

Concept ACK.

• aac6548
  • CChainParams m_params is made a public member of class CChainState.
  • chainstate.m_params is used instead of global Params() in AcceptToMemoryPool in validation.cpp. (with changes in fuzz/tx_pool.cpp done in PR 23465)
• 20df92b
  • chainstate.m_params is used instead of global Params() in validation.cpp inside functions like ProcessNewPackage(), ProcessNewBlockHeaders(), LoadMempool() and PopulateAndValidateSnapshot().
  • The function signature of LoadBlockIndexDB() is changed to include the first argument as Consensus::Params and call site updated in order to avoid the global call to Params() within the function.

I'm also curious to know if there's any added advantage in making m_params public (in comparison with using getters/setters)?

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🐙 This pull request conflicts with the target branch and needs rebase.

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@lsilva01 are you still interested in working on this?

Pretty sure this is already done in master?