OpenTelemetry and real-time logging of errors and events

[h-arlt]

At the moment, XLT offers support real-time reporting of metrics using Graphite only. But the need came up to support real-time reporting of other telemetry data such as errors and events which is not possible with Graphite. Furthermoe, Graphite lacks popularity and active development.

For this reasons, we should add support for OpenTelemetry - de-facto industry standard for sending, receiving and processing telemetry data such as metrics, traces and logs - to XLT and use it to log errors and events in real-time.