Tooltip outside of screen

[LinqLover]

Describe the bug
When hovering a node of the flamegraph in the bottom right corner of my screen, the tooltip will be outside of the screen so the user cannot view it and the document's size will grow and scrollbars will be added to the window.

Reproduced on Desktop, but should occur on mobile as well (Chrome).

Expected behavior
Position the tooltip above the node instead of below it when hovering. Clamp the x coordinate to keep it inside the screen.

Additional context
The relevant logic seems to be here:

d3-flame-graph/src/tooltip.js

Lines 35 to 36 in ba6b2d0

	.style('left', event.pageX + 5 + 'px')
	.style('top', event.pageY + 5 + 'px')

A solution as proposed here could be implemented:

https://stackoverflow.com/a/28540519/13994294

Are you accepting PRs?

[LinqLover]

Possibly related to #109