Change: Log changes to sandbox settings. (#13267)

One of the features of cheats is that there is a record of a cheat being used.

As cheats are slowly ending up in settings instead, add a flag so that changes to these sandbox settings are logged.

src/settings.cpp

@@ -1604,7 +1604,7 @@ void IntSettingDesc::ChangeValue(const void *object, int32_t newval) const
 	this->Write(object, newval);
 	if (this->post_callback != nullptr) this->post_callback(newval);
 
-	if (this->flags & SF_NO_NETWORK) {
+	if (HasFlag(this->flags, SF_NO_NETWORK) || HasFlag(this->flags, SF_SANDBOX)) {
 		_gamelog.StartAction(GLAT_SETTING);
 		_gamelog.Setting(this->GetName(), oldval, newval);
 		_gamelog.StopAction();

src/settings_internal.h

@@ -27,6 +27,7 @@ enum SettingFlag : uint16_t {
 	SF_NOT_IN_SAVE             = 1 << 10, ///< Do not save with savegame, basically client-based.
 	SF_NOT_IN_CONFIG           = 1 << 11, ///< Do not save to config file.
 	SF_NO_NETWORK_SYNC         = 1 << 12, ///< Do not synchronize over network (but it is saved if SF_NOT_IN_SAVE is not set).
+	SF_SANDBOX                 = 1 << 13, ///< This setting is a sandbox setting.
 };
 DECLARE_ENUM_AS_BIT_SET(SettingFlag)
 

src/table/settings/difficulty_settings.ini

@@ -301,6 +301,7 @@ cat      = SC_BASIC
 
 [SDT_BOOL]
 var      = difficulty.infinite_money
+flags    = SF_SANDBOX
 def      = false
 str      = STR_CONFIG_SETTING_INFINITE_MONEY
 strhelp  = STR_CONFIG_SETTING_INFINITE_MONEY_HELPTEXT