Codechange: Add a priority field to TimerGameTick::TPeriod

Use this as the primary sort key for TimerGameTick::TPeriod,
to avoid container sort order changes on timer period saveload.
See: #12509

src/company_cmd.cpp

@@ -635,7 +635,7 @@ Company *DoStartupNewCompany(bool is_ai, CompanyID company = INVALID_COMPANY)
 }
 
 /** Start a new competitor company if possible. */
-TimeoutTimer<TimerGameTick> _new_competitor_timeout(0, []() {
+TimeoutTimer<TimerGameTick> _new_competitor_timeout({ TimerGameTick::Priority::COMPETITOR_TIMEOUT, 0 }, []() {
 	if (_game_mode == GM_MENU || !AI::CanStartNew()) return;
 	if (_networking && Company::GetNumItems() >= _settings_client.network.max_companies) return;
 
@@ -776,7 +776,7 @@ void OnTick_Companies()
 		/* Randomize a bit when the AI is actually going to start; ranges from 87.5% .. 112.5% of indicated value. */
 		timeout += ScriptObject::GetRandomizer(OWNER_NONE).Next(timeout / 4) - timeout / 8;
 
-		_new_competitor_timeout.Reset(std::max(1, timeout));
+		_new_competitor_timeout.Reset({ TimerGameTick::Priority::COMPETITOR_TIMEOUT, static_cast<uint>(std::max(1, timeout)) });
 	}
 
 	_cur_company_tick_index = (_cur_company_tick_index + 1) % MAX_COMPANIES;