Pipeline-telemetry

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* Added ``TelemetryMixin`` class to enable easy including of telemetry update
methods in any datapipeline class.

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* Added ``process_telemetry_counters_in_return_value`` helper method to easily
add retrieve and process TelemetryCounter objects from a return value object.
* Added ``process_return_value`` helper method to process both ErrorCode and
TelemetryCounter objects from a return value object.
* Added more documentation

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* Added ``add_errors_from_return_value`` helper method to easily add the errors
from a ``ReturnValueWithStatus`` object from ``error-manager`` package.
* Automatically initialize a missing sub_process when a telemetry counter is
added to the telemetry instance.

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* Added ``add_single_usage_telemetry`` decorator to be used for single usage
* telemetry objects

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* Added ``telemetry_type`` and ``io_time_in_seconds`` attributes to Telemetry
* object including a method to increase ``io_time_in_seconds``.

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* Added ``traffic_light`` attribute to Telemetry object indicating the success
state of the datapipeline process that is reporting on
* Some minor refactoring