Add ByteToHexStr() and WordToHexStr() (PR #1064)

- Simplify common StrFormat(), especially in Debugger (changes upcoming)
- Add helpers StrAppendByteAsHex() and StrAppendWordAsHex()
- Add helpers StrBufferAppendByteAsHex() and StrBufferAppendWordAsHex() for plain string buffer

source/LanguageCard.cpp

@@ -443,7 +443,7 @@ bool Saturn128K::LoadSnapshot(YamlLoadHelper& yamlLoadHelper, UINT version)
 		}
 
 		// "Memory Bankxx"
-		std::string memName = GetSnapshotMemStructName() + StrFormat("%02X", uBank);
+		std::string memName = GetSnapshotMemStructName() + ByteToHexStr(uBank);
 
 		if (!yamlLoadHelper.GetSubMap(memName))
 			throw std::runtime_error("Memory: Missing map name: " + memName);