[logging] introduce LogWarnOnError() for standardized error logging (#9996)

This commit adds `LogWarnOnError()` to emit warning-level logs on
errors. The emitted log includes the error code. This replaces custom
`LogError()` across modules, simplifying the code.

src/core/thread/dua_manager.cpp

@@ -158,7 +158,7 @@ Error DuaManager::GenerateDomainUnicastAddressIid(void)
     }
     else
     {
-        LogWarn("Generate DUA: %s", ErrorToString(error));
+        LogWarnOnError(error, "generate DUA");
     }
 
     return error;
@@ -548,7 +548,7 @@ exit:
         UpdateCheckDelay(kNoBufDelay);
     }
 
-    LogInfo("PerformNextRegistration: %s", ErrorToString(error));
+    LogWarnOnError(error, "perform next registration");
     FreeMessageOnError(message, error);
 }