Fetches list of txns from validator, optionally filtered by id.

        Request:
            query:
                - head: The id of the block to use as the head of the chain
                - id: Comma separated list of txn ids to include in results

        Response:
            data: JSON array of Transaction objects with expanded headers
            head: The head used for this query (most recent if unspecified)
            link: The link to this exact query, including head block
            paging: Paging info and nav, like total resources and a next link

async def list_transactions(self, request):
        """Fetches list of txns from validator, optionally filtered by id.

        Request:
            query:
                - head: The id of the block to use as the head of the chain
                - id: Comma separated list of txn ids to include in results

        Response:
            data: JSON array of Transaction objects with expanded headers
            head: The head used for this query (most recent if unspecified)
            link: The link to this exact query, including head block
            paging: Paging info and nav, like total resources and a next link
        """
        paging_controls = self._get_paging_controls(request)
        validator_query = client_transaction_pb2.ClientTransactionListRequest(
            head_id=self._get_head_id(request),
            transaction_ids=self._get_filter_ids(request),
            sorting=self._get_sorting_message(request, "default"),
            paging=self._make_paging_message(paging_controls))

        response = await self._query_validator(
            Message.CLIENT_TRANSACTION_LIST_REQUEST,
            client_transaction_pb2.ClientTransactionListResponse,
            validator_query)

        data = [self._expand_transaction(t) for t in response['transactions']]

        return self._wrap_paginated_response(
            request=request,
            response=response,
            controls=paging_controls,
            data=data)