Figure out how to display nice notebook previews of radar datasets

[thomasteisberg]

We need to load in the parameter structures, but they're deeply nested dictionaries and the previews of them look awful with the default xarray _repr_html_.

Current workaround: We now have a custom accessor that provides a new _repr_html_ that collapses nested dictionaries, similar to how other elements of xarray datasets can be collapsed. The problem is that you have to use ds.xopr to see it, rather than just ds.

Best case scenario would be to upstream the collapsible dictionaries, but it may be too niche a use case for xarray. PR is here: pydata/xarray#10663

Other options:

• Stick with the accessor
• Subclass Dataset
• Maybe make a custom object type for the params dictionaries, which could at least override _str_ and return a shorter (but plain text only) preview?

[thomasteisberg]

Update: We've now embraced the accessor syntax and have put more stuff under the .xopr namespace. It would still be nice if we could figure out how to upstream some version of an improved attrs _repr_html_, however this would require buy-in from the xarray maintainers that we may or may not get.