Merge bitcoin/bitcoin#33724: refactor: Return uint64_t from GetSerializeSize

fa6c0bedd3 refactor: Return uint64_t from GetSerializeSize (MarcoFalke)
fad0c8680e refactor: Use uint64_t over size_t for serialized-size values (MarcoFalke)
fa4f388fc9 refactor: Use fixed size ints over (un)signed ints for serialized values (MarcoFalke)
fa01f38e53 move-only: Move CBlockFileInfo to kernel namespace (MarcoFalke)
fa2bbc9e4c refactor: [rpc] Remove cast when reporting serialized size (MarcoFalke)
fa364af89b test: Remove outdated comment (MarcoFalke)

Pull request description:

  Consensus code should arrive at the same conclusion, regardless of the architecture it runs on. Using architecture-specific types such as `size_t` can lead to issues, such as the low-severity [CVE-2025-46597](https://bitcoincore.org/en/2025/10/24/disclose-cve-2025-46597/).

  The CVE was already worked around, but it may be good to still fix the underlying issue.

  Fixes https://github.com/bitcoin/bitcoin/issues/33709 with a few refactors to use explicit fixed-sized integer types in serialization-size related code and concluding with a refactor to return `uint64_t` from `GetSerializeSize`. The refactors should not change any behavior, because the CVE was already worked around.

ACKs for top commit:
  Crypt-iQ:
    crACK fa6c0bedd3
  l0rinc:
    ACK fa6c0bedd3
  laanwj:
    Code review ACK fa6c0bedd3

Tree-SHA512: f45057bd86fb46011e4cb3edf0dc607057d72ed869fd6ad636562111ae80fea233b2fc45c34b02256331028359a9c3f4fa73e9b882b225bdc089d00becd0195e

src/node/blockstorage.cpp

@@ -35,6 +35,7 @@
 #include <util/signalinterrupt.h>
 #include <util/strencodings.h>
 #include <util/syserror.h>
+#include <util/time.h>
 #include <util/translation.h>
 #include <validation.h>
 
@@ -151,6 +152,11 @@ bool BlockTreeDB::LoadBlockIndexGuts(const Consensus::Params& consensusParams, s
 
     return true;
 }
+
+std::string CBlockFileInfo::ToString() const
+{
+    return strprintf("CBlockFileInfo(blocks=%u, size=%u, heights=%u...%u, time=%s...%s)", nBlocks, nSize, nHeightFirst, nHeightLast, FormatISO8601Date(nTimeFirst), FormatISO8601Date(nTimeLast));
+}
 } // namespace kernel
 
 namespace node {