Partially revert 8e8da92 to go back to behavior of d578ed

We never inject series into chart implicitly. Only filters selected by
end-user are displayed on chart. This guarantuee maximum flexibility
and coherence with ignored elements.

Also all filters are always returned, because we cannot know what filter
may have been influenced by the projection.
Move test data into its own folder
Always refresh the filter displayed on chart
Hide alternative series if data are identical to original series #2848