Replace boost with C++17 std equivalents, upgrade LZ4 to 1.10.0

- boost::tuple → std::tuple (serialize.h, miner.cpp, script.cpp, walletdb.cpp)
- boost::shared_ptr → std::shared_ptr (trianglesrpc.cpp)
- boost::variant → std::variant for CTxDestination (script.h)
- boost::get → std::get_if (main.cpp, rpcblockchain.cpp, coincontroldialog.cpp, wallet.cpp)
- boost::apply_visitor → std::visit (base58.h, script.cpp, rpcwallet.cpp, test/base58_tests.cpp)
- boost::static_visitor removed from all visitor classes
- boost::lexical_cast → std::to_string/std::stoll (smessage.cpp, rpcsmessage.cpp)
- Removed unused boost/lexical_cast.hpp includes (rest.cpp, trianglesrpc.cpp)
- Removed boost/variant/get.hpp include (rpcdump.cpp)
- Upgraded vendored LZ4 from 1.1.3 to 1.10.0
- Updated LZ4_compress() → LZ4_compress_default() (smessage.cpp)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/rpcblockchain.cpp

@@ -431,13 +431,13 @@ static bool ParseAddress(const std::string& strAddr, int& nType, uint160& hashBy
         return false;
 
     CTxDestination dest = addr.Get();
-    const CKeyID* keyId = boost::get<CKeyID>(&dest);
+    const CKeyID* keyId = std::get_if<CKeyID>(&dest);
     if (keyId) {
         nType = ADDR_TYPE_P2PKH;
         hashBytes = *keyId;
         return true;
     }
-    const CScriptID* scriptId = boost::get<CScriptID>(&dest);
+    const CScriptID* scriptId = std::get_if<CScriptID>(&dest);
     if (scriptId) {
         nType = ADDR_TYPE_P2SH;
         hashBytes = *scriptId;