Merge bitcoin/bitcoin#28423: kernel: Remove protocol.h/netaddress.h/compat.h from kernel headers

d506765199 [refactor] Remove compat.h from kernel headers (TheCharlatan)
36193af47c [refactor] Remove netaddress.h from kernel headers (TheCharlatan)
2b08c55f01 [refactor] Add CChainParams member to CConnman (TheCharlatan)
f0d1d8b35c [refactor] Add missing includes for next commit (TheCharlatan)
534b314a74 kernel: Move MessageStartChars to its own file (TheCharlatan)
9be330b654 [refactor] Define MessageStartChars as std::array (TheCharlatan)
37e2b01113 [refactor] Allow std::array<std::byte, N> in serialize.h (MarcoFalke)

Pull request description:

  This removes the non-consensus critical `protocol.h` and `netaddress.h` headers from the kernel headers. With this patch, they are no longer required to include in order to use the libbitcoinkernel library. This also allows for the removal of the `compat.h` header from the kernel headers.

  As an added future benefit it also reduces the number of of kernel headers that include the platform specific `bitcoin-config.h`.

  For those interested, the currently required kernel headers can be inspected visually with the [sourcetrail](https://github.com/CoatiSoftware/Sourcetrail) tool by looking at the required includes of `bitcoin-chainstate.cpp`.

  ---

  This is part of the [libbitcoinkernel project](https://github.com/bitcoin/bitcoin/issues/27587), namely its stage 1 step 3: Decouple most non-consensus headers from libbitcoinkernel.

ACKs for top commit:
  stickies-v:
    re-ACK d506765
  hebasto:
    ACK d506765199.
  ajtowns:
    utACK d506765199
  MarcoFalke:
    lgtm ACK d506765199 🍛

Tree-SHA512: 6f90ea510a302c2927e84d16900e89997c39b8ff3ce9d4effeb8a134bd29cc52bd9e81e51aaa11f7496bad00025b78a58b88c5a9e0bb3f4ebbe9a76309215fb7

src/node/blockstorage.cpp

@@ -11,6 +11,7 @@
 #include <flatfile.h>
 #include <hash.h>
 #include <kernel/chainparams.h>
+#include <kernel/messagestartchars.h>
 #include <logging.h>
 #include <pow.h>
 #include <reverse_iterator.h>
@@ -21,6 +22,7 @@
 #include <util/batchpriority.h>
 #include <util/fs.h>
 #include <util/signalinterrupt.h>
+#include <util/strencodings.h>
 #include <util/translation.h>
 #include <validation.h>
 
@@ -927,12 +929,12 @@ bool BlockManager::ReadRawBlockFromDisk(std::vector<uint8_t>& block, const FlatF
     }
 
     try {
-        CMessageHeader::MessageStartChars blk_start;
+        MessageStartChars blk_start;
         unsigned int blk_size;
 
         filein >> blk_start >> blk_size;
 
-        if (memcmp(blk_start, GetParams().MessageStart(), CMessageHeader::MESSAGE_START_SIZE)) {
+        if (blk_start != GetParams().MessageStart()) {
             return error("%s: Block magic mismatch for %s: %s versus expected %s", __func__, pos.ToString(),
                          HexStr(blk_start),
                          HexStr(GetParams().MessageStart()));