refactor: remove dependencies of CChainState on CMasternodeSync

[knst]

depends on #7178

Issue being fixed or feature implemented

The class CMasternodeSync is about network communication. It should not be a direct dependency of CChainState.

Most changes are split-off from #7178 to keep 7178 tidy.

What was done?

• fixed Regression tests of miner to be compatible with Instant Send
• Instant Send doesn't use CMasternodeSync status during the checks inside 'RejectConflictingBlocks` (split from 7178)
• CMNPaymentsProcessor uses a new helper CGovernanceManager::IsValidAndSynced instead direct usages of CMasternodeSync

Usages of RejectConflictingBlocks are:

• ChainLockSigner::TrySignChainTip. This IsBlockchainSynced still checked directly
• Behavior of Miner BlockAssembler::TestPackageTransactions is changed now. But it should not affect anything beside regression tests, because blocks are not expected to be mined when sync is not done yet.
• CChainState::ConnectBlock uses it indirectly over helper CChainstateHelper::ShouldInstantSendRejectConflicts

How Has This Been Tested?

Run unit & functional tests.

Breaking Changes

N/A

Checklist:

Go over all the following points, and put an x in all the boxes that apply.

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have added or updated relevant unit/integration/functional/e2e tests
• I have made corresponding changes to the documentation
• I have assigned this pull request to a milestone (for repository code-owners and collaborators only)

[github-actions]

This pull request has conflicts, please rebase.

[github-actions]

⚠️ Potential Merge Conflicts Detected

This PR has potential conflicts with the following open PRs:

• feat(llmq): add trustless quorum proof chain generation and verification #7107 - feat(llmq): add trustless quorum proof chain generation and verification

Please coordinate with the authors of these PRs to avoid merge conflicts.