Retrieve all readings received between the start-time and end-time parameters. This endpoint allows
the readings for all installed sensors to be retrieved in a single endpoint call. The maximum number
of readings that will be returned for a single request is 5000 or the passed page-size parameters.
If the requested time range results in more readings than the limit, a links.next property is
returned in the response body with the path that should be used to get the next page of readings.
Unlike the sensor specific endpoint /sensors/{macAddress}/readings, the list of readings returned
from this endpoint uses the timestamp the reading was received by the central device (not the
timestamp the gateway received the reading) to order the responses. If a gateway is unable to connect
to the central device for a period of time it is possible reading will be received out of order from when
the sensor recorded the measurement.