Fix enum behavior for python 3.11

closes #8221
closes #8217

freqtrade/enums/candletype.py

@@ -13,6 +13,9 @@ class CandleType(str, Enum):
     FUNDING_RATE = "funding_rate"
     # BORROW_RATE = "borrow_rate"  # * unimplemented
 
+    def __str__(self):
+        return f"{self.name.lower()}"
+
     @staticmethod
     def from_string(value: str) -> 'CandleType':
         if not value:

freqtrade/enums/rpcmessagetype.py

@@ -37,5 +37,8 @@ class RPCRequestType(str, Enum):
     WHITELIST = 'whitelist'
     ANALYZED_DF = 'analyzed_df'
 
+    def __str__(self):
+        return self.value
+
 
 NO_ECHO_MESSAGES = (RPCMessageType.ANALYZED_DF, RPCMessageType.WHITELIST, RPCMessageType.NEW_CANDLE)