Add HyperoptState enum and container class

freqtrade/enums/hyperoptstate.py

@@ -0,0 +1,12 @@
+from enum import Enum
+
+
+class HyperoptState(Enum):
+    """ Hyperopt states """
+    STARTUP = 1
+    DATALOAD = 2
+    INDICATORS = 3
+    OPTIMIZE = 0
+
+    def __str__(self):
+        return f"{self.name.lower()}"