OrderTypeValues should be in enums

freqtrade/enums/__init__.py

@@ -1,5 +1,6 @@
 # flake8: noqa: F401
 from freqtrade.enums.backteststate import BacktestState
+from freqtrade.enums.ordertypevalue import OrderTypeValues
 from freqtrade.enums.rpcmessagetype import RPCMessageType
 from freqtrade.enums.runmode import NON_UTIL_MODES, OPTIMIZE_MODES, TRADING_MODES, RunMode
 from freqtrade.enums.selltype import SellType

freqtrade/enums/ordertypevalue.py

@@ -0,0 +1,6 @@
+from enum import Enum
+
+
+class OrderTypeValues(str, Enum):
+    limit = 'limit'
+    market = 'market'