* heatmap: fix converting error when series contains 0 and log scale is selected, issue #8884

* heatmap: fix app crash when Y min set to 0 with log scale

* heatmap: fix tooltip for 'zero' buckets in log scale

* heatmap: fix tooltip histogram for log scales

* heatmap: fix flicker of the highlighted element

this was caused by too often fired mouseenter/mouseleave events

* heatmap: fix missing X axis option for log scales

* heatmap: fix missing zero bucket in tooltip histogram