add deprecation warning for mapbox traces and mapbox subplot

[archmoj]

With the introduction of scattermap, choroplethmap and densitymap as well as map subplots in #7060 this PR adds deprecation warnings to the description of scattermapbox, choroplethmaboxp and densitymapbox as well as mapbox subplots.

@plotly/plotly_js

[red-patience]

Okay for me if the style is consistent with other messages in this repo (not super familiar with its conventions)

[ndrezn]

Previous deprecation warning example for reference: #5447

[ndrezn]

It doesn't look like these deprecations will appear in the console if these traces are used... is that correct? I would expect a console warning

[archmoj]

It doesn't look like these deprecations will appear in the console if these traces are used... is that correct? I would expect a console warning

A warning is now added in the console when using a mapbox subplot.

[archmoj]

@emilykl Can I have your review on this PR please?

[emilykl]

@archmoj @ndrezn I would suggest changing the wording of the first sentence to

{trace name} trace is deprecated and will be removed in the next major release.

to give a sense of urgency.

[ndrezn]

Once we have the link for the migration docs available, we should include that link directly in this deprecation warning.

[archmoj]

@ndrezn Would you please take over this PR?

[ndrezn]

@archmoj , I've added the link where the JS migration guide will live (it is not live yet). I believe that plot-schema.json is autogenerated, I haven't run the build locally before -- could you regenerate this and add to the PR? I think then this PR is good to merge! 🥳