The default behaviour of put is not sane enough for unknown object types

[augustebaum]

Is your feature request related to a problem? Please describe.

The current default when an unknown object type is put is to raise an ItemTypeError.

The user has two solutions if they want to store their object in skore:

• Use MediaItem, i.e. rather than:

project.put("key", my_obj)

write for example

project.put_item("key", MediaItem.factory(my_obj_as_bytes_or_str, media_type="text/html"))

This means the user has the responsibility of passing the media type and to convert their object to bytes or string form, which they are unlikely to do in practice.

• Open an issue to ask for a new Item type (or open a PR adding it). See FEAT: Support a skrub TableReport #806 for example.

Both of these solutions lower the usability of skore.

Describe the solution you'd like

We should support put for any object that has a _repr_html_ method, and when this is the case we do the conversion to MediaItem ourselves.

In the future we can also consider other media types by detecting other _repr_xxx_ methods, e.g. by looking first for _repr_html_, then _repr_svg_, then _repr_png_, etc. We might also make use of _repr_mimebundle_.

Describe alternatives you've considered, if relevant

No response

Additional context

This issue is derived from #810 (comment)