list items should return "None" when there are no items to list

[bradh11]

Current behavior for most methods is to Fault with a "None is not subscriptable: when running a method to get a list of items (if no items exist). The fix will require changing from

    def get_sip_trunks(
        self, tagfilter={"name": "", "sipProfileName": "", "callingSearchSpaceName": ""}
    ):
        try:
            return self.client.listSipTrunk({"name": "%"}, returnedTags=tagfilter)[
                "return"
            ]["sipTrunk"]
        except Fault as e:
            return e

and change it to the following:

    def get_sip_trunks(
        self, tagfilter={"name": "", "sipProfileName": "", "callingSearchSpaceName": ""}
    ):
        try:
            response = self.client.listSipTrunk({"name": "%"}, returnedTags=tagfilter)["return"]
            if response:
                return response["sipTrunk"]
            else:
                return response
        except Fault as e:
            return e

this would need to be done for all methods to list items