Heatmap layer integration: revert temporary heatmap-as-default
- two new (hidden) settings to control switch to heatmap
- Heatmap is optional if result count exceeds heatmapSuggestionThreshold
- Heatmap is automatic if result count exceeds maxResultsMarkers
Fix enable=false case in enableZoomControls()
Fix issues in bounds management, visibility of Zoom-to-bounds button
- drawResultMarkers() would reset network bounds when session list is empty
- when clearing all data call updateBoundsToNetwork() to reset bounds and hide the button