Avoid hiding tooltip on first hover of previous clicked annotation

[eweitz]

This fixes an edge case bug in Gene Leads where the tooltip / popover would annoyingly disappear.

To reproduce:

1. Click an annotation, A
2. Hover over another annotation, B
3. Hover outside annotation B
4. Wait for tooltip B to disappear
5. Hover over label of annotation A
6. Hover over tooltip A
7. Note tooltip A unexpectedly disappears

Now, the tooltip persists in this scenario. The two videos below demonstrate how the problem and solution look.

Before: tooltip disappears

Repeat_hover_before__Gene_leads_ideogram_2024-12-02.mov

After: tooltip persists

Repeat_hover_after__Gene_leads_ideogram_2024-12-02.mov