Add a dark theme for the tablereport

[jeromedockes]

rough draft to start reorganizing the colors & add a dark variant.
I'm opening the PR to have a trace of it but we don't have to use it we can start over from scratch based on #1165

[jeromedockes]

the colors are very random and need to be changed but I think at this point the report should be readable both in light & dark modes

(see for example the rendered doc )

[GaelVaroquaux]

Did you try it with various vscode dark theme (there are a few)?

[jeromedockes]

I would rather not try to match the exact theme with a finer granularity than dark/light. IMO we should hard code a full set of colors for light mode and for dark mode and just match the mode rather than reuse colors from a vscode theme. because vscode is just one of the many places report can be displayed, and also I assume that as in any editor there is a myriad of themes and each user can come up with their own. so I think if we try to reuse colors from vscode themes we can end up having to maintain many variants, spend time checking them every time we change something, and most importantly risk having some parts unreadable due to low contrast in some environments

[GaelVaroquaux]

IMO we should hard code a full set of colors for light mode and for dark mode and just match the mode rather than reuse colors from a vscode theme.

I would agree. It's just about checking that it is visible and legible in all settings.