allow hover labels to extend to the edges of the plot

[alexcjohnson]

fixes #527

@etpinard another quick bugfix for you: Allow hover labels to push out not just to the edges of the subplot but to the edges of the graph div.

There's one downside to this fix: The axis label can get partially covered by point labels in certain extreme cases:

The common label is supposed to say "day 1" and the "1" is mostly covered. If this label were much longer, more of it would be hidden. To my mind this is a good tradeoff, as a) the y labels are usually more important, so it's better to show as many of these as you can, and b) you can always switch to "closest" mode to narrow in on what info is displayed.

[etpinard]

To my mind this is a good tradeoff, as a) the y labels are usually more important, so it's better to show as many of these as you can, and b) you can always switch to "closest" mode to narrow in on what info is displayed.

I agree. This is a good tradeoff.

Nice fix and test 💃