Runtime configuration of diagnostics related to the RX-DO-TX phases

[marcoaccame]

This PR introduces the runtime configuration via xml files of the diagnostics associated to the execution loop.
In particular, it will be possible to:

• enable / disable the diagnostics about execution overflow of the RX, DO and TX phases. The default is enabled.
• enable / disable the diagnostics about statistics of the RX, DO and TX phases. It will be reported minimum, average and maximum durations of the phases over a period configurable between 1 and 600 seconds. The default is disabled.