JFG-783 Change line - legend relation in all plots

+ creating PlotSeriesDto object , that represent single plot, from one place for metric and plots.
+ MetricDto do not contain superfluous PlotDatasetDto that represent same values from MetricDto.values in other way.
+ create legend tree.
- plots rendering in old way
- new legend tree presents in  panel bellow plot
propose ```return Collections.epmtyList();```

we are usually doing in this way