docs: Use Popup in Maplibre/Mapbox getting started example

[felixpalmer]

Closes #8530

Background

This is a common use case and it isn't trivial as it isn't obvious that it isn't possible to do this with the "reverse-controlled" React pattern.

Change List

• Use Popup component instead of alert()

[coveralls]

coverage: 89.563%. remained the same
when pulling e79734a on felix/maplibre-popup
into f1a163a on master.

[Pessimistress]

Should the mapbox example be updated as well?

[chrisgervang]

Definitely a more useful example this way. Though, I'm not sure I understand your comment about reverse-control since this isn't that. Those examples are all in website whereas this is considered to be using the overlay pattern.

[felixpalmer]

@chrisgervang what I was getting at regarding "reverse-controlled" is that newcomers will look at our examples (get-started or website) and pick whatever looks most appropriate, not realizing that they've chosen an integration mode. Then when it comes to adding a Popup, they might get stuck if they "accidentally" picked a reverse-controlled pattern.

[coveralls]

coverage: 89.404% (-0.2%) from 89.563%
when pulling 3d1ee38 on felix/maplibre-popup
into f1a163a on master.

[coveralls]

coverage: 89.404%. remained the same
when pulling 3188b94 on felix/maplibre-popup
into 0af27a1 on master.

[coveralls]

coverage: 89.404%. remained the same
when pulling 3fddcf7 on felix/maplibre-popup
into 0af27a1 on master.