… be sent (PIVX-Project#2783)

* Introduce "qsendrecsigs" to indicate that plain recovered sigs should be sent

Full nodes, including masternodes, will send this message automatically.
Other node implementations (e.g. SPV) are usually not interested and would
not send this message.

* Use std::atomic<bool> instead of std::atomic_bool

Not related to this PR, but a small enough change to include it here as
well.

901976a Stop tracking interested/participating nodes and send/announce to MNAUTH peers (#2798) (Alexander Block)
59dfdc2 update bestChainLockWithKnownBlock in AcceptedBlockHeader (Alessandro Rezzi)
bd0a3f8 Introduce "qsendrecsigs" to indicate that plain recovered sigs should be sent (#2783) (Alexander Block)
846fd9a Make LLMQ/InstantSend/ChainLocks code less spammy (#2781) (Alexander Block)
1a52ad0 Fix LogPrintf call in ::DoInvalidateBlock (Alessandro Rezzi)
e3c5eef Multiple fixes/refactorings for ChainLocks (#2765) (Alexander Block)
9dda5d2 Implement LLMQ based InstantSend (#2735) (Alexander Block)
149e3e3 Various small cleanups (#2761) (UdjinM6)
cc7450d Use ReleaseNodeVector and CopyNodeVector in PIVX specific code (Alessandro Rezzi)
ed463a6 Do not hold cs_vNodes in CSigSharesManager::SendMessages() for too long (#2758) (UdjinM6)
cd1809f Implement persistence for LLMQ based InstantSend (#2756) (Alexander Block)
924ee8f Don't be too harsh for invalid CLSIGs (#2742) (Alexander Block)
f255314 Fix banning when local node doesn't have the vvec (#2739) (Alexander Block)

Pull request description:

  each commit backports a different PR. The PR number is in the commit message.

  There are also 3 extra (trivial) commits added by me

ACKs for top commit: 901976a
  Duddino:
    utACK 901976a
  Liquid369:
    uTACK 901976a

Tree-SHA512: 70b53ae3fc014c23964cae3452f6c8270d96b3b375c0f172e04039ba6f3b537d56c38677e5e4005c8b810a82b447a64fc978c2d63344b9e9736ceff7db162a18