Use the properties of the slo checker and add lag trend percent

Closes #243

See merge request !172

The percentage lag trend is at the moment only available for the NumSensors
load type, because for NumNestedGroups it makes no sense.

Specific slo checker should be defined with a propertie map to be more generic.
Further add a lag trend percent slo, which use a percentage of the defined load
to compute the allowed threshold.

>
> update benchark crd and example benchmark,
> renaming, formatting,
> fix test and small issues in different classes

Add basic support for loading resources via a so called resource set either from configmap or from file system

Enhance Code Quality

Closes #209

See merge request !168