[MM-57826] Make sure the original errors are wrapped when AppErrors are returned (#26771)

Co-authored-by: Ibrahim Serdar Acikgoz <serdaracikgoz86@gmail.com>

server/channels/api4/data_retention.go

@@ -373,7 +373,7 @@ func searchChannelsInPolicy(c *Context, w http.ResponseWriter, r *http.Request)
 
 	channelsJSON, jsonErr := json.Marshal(channels)
 	if jsonErr != nil {
-		c.Err = model.NewAppError("searchChannelsInPolicy", "api.marshal_error", nil, jsonErr.Error(), http.StatusInternalServerError)
+		c.Err = model.NewAppError("searchChannelsInPolicy", "api.marshal_error", nil, "", http.StatusInternalServerError).Wrap(jsonErr)
 		return
 	}
 
@@ -458,7 +458,7 @@ func getTeamPoliciesForUser(c *Context, w http.ResponseWriter, r *http.Request)
 
 	js, jsonErr := json.Marshal(policies)
 	if jsonErr != nil {
-		c.Err = model.NewAppError("getTeamPoliciesForUser", "api.marshal_error", nil, jsonErr.Error(), http.StatusInternalServerError)
+		c.Err = model.NewAppError("getTeamPoliciesForUser", "api.marshal_error", nil, "", http.StatusInternalServerError).Wrap(jsonErr)
 		return
 	}
 	w.Write(js)
@@ -486,7 +486,7 @@ func getChannelPoliciesForUser(c *Context, w http.ResponseWriter, r *http.Reques
 
 	js, jsonErr := json.Marshal(policies)
 	if jsonErr != nil {
-		c.Err = model.NewAppError("getChannelPoliciesForUser", "api.marshal_error", nil, jsonErr.Error(), http.StatusInternalServerError)
+		c.Err = model.NewAppError("getChannelPoliciesForUser", "api.marshal_error", nil, "", http.StatusInternalServerError).Wrap(jsonErr)
 		return
 	}
 	w.Write(js)