added toAron and toJSON methods for metadata

this now allows to save metadata into a json file using python

armarx_memory/aron/data/dto/common/metadata.py

 from dataclasses import dataclass
 
+from ...variant import AronDict
 from armarx_memory.aron.data.variant import AronDict, AronDouble, AronLong
 from armarx_memory.aron.data.dto.aron_dto import AronDTOBase
 
@@ -37,4 +38,16 @@ class Metadata(AronDTOBase):
 
         return cls(timeArrived=arrived.value, timeSent=sent.value, timeReferenced=referenced.value, timeStored=stored.value)
     
-
+    def toAron(self) -> AronDict:
+        elements = {
+            "__ENTITY_METADATA__CONFIDENCE" : AronDouble(1.0, "__ENTITY_METADATA__CONFIDENCE"),
+            "__ENTITY_METADATA__TIME_ARRIVED": AronLong(self.timeArrived, "__ENTITY_METADATA__TIME_ARRIVED"),
+            "__ENTITY_METADATA__TIME_REFERENCED": AronLong(self.timeReferenced, "__ENTITY_METADATA__TIME_REFERENCED"),
+            "__ENTITY_METADATA__TIME_SENT": AronLong(self.timeSent, "__ENTITY_METADATA__TIME_SENT"),
+            "__WRITER_METADATA__TIME_STORED": AronLong(self.timeStored, "__WRITER_METADATA__TIME_STORED")
+        }
+        aron_dict = AronDict(elements=elements, path=[])
+        return aron_dict
+    
+    def toJSON(self):
+        return self.toAron().toJSON()