ClassifierRequested event needs parameters

[MerrionComputing]

Now that classifiers can accept parameters, we need these to be logged in the ClassifierRequested event.
(There may be constrains on how many parameters can be passed)

[MerrionComputing]

Decision is to have each parameter added as its own event ( ClassifierRequestParameterSet.cs ) - this allows for reaction to a particular parameter and also reduces the risk of the event getting too large.