feat: tooltips

[lopezvoliver]

This adds ipyleaflet.Tooltip in order to use leaflet tooltips.

The user can create a "standalone" tooltip at a given location, or bind a Tooltip widget to a Layer, as demonstrated below:

@martinRenou @arjxn-py or any other maintainer, please review =)

[martinRenou]

Looks great! Thanks a lot for adding documentation.

I've only found a small issue with the non-permanent tooltips, they seem to disappear whichever the location where you click, not only when you click on them:

Screencast.From.2025-06-19.13-42-17.mp4

[lopezvoliver]

Looks great! Thanks a lot for adding documentation.

I've only found a small issue with the non-permanent tooltips, they seem to disappear whichever the location where you click, not only when you click on them:

Screencast.From.2025-06-19.13-42-17.mp4

I just tested this and it's the same in leaflet.js:

https://jsfiddle.net/lopezvoliver/37r4xacw/8/

I will update the comment in the doc.

[martinRenou]

Thanks!