vscode: support flexible plots

[pared]

• [ ] ❗ I have followed the Contributing to DVC checklist.

• [ ] 📖 If this PR requires documentation updates, I have created a separate PR (or issue, at least) in dvc.org and linked it here.

Thank you for the contribution - we'll try to review it as soon as possible. 🙏

Change required for iterative/vscode-dvc#2379 Related iterative/vscode-dvc#1757

[dberenbaum]

@pared This seems to break bar plots at the moment. The values in the HTML are missing rev and formatted like:

    {
        "Feature": "data frame",
        "Mean decrease in impurity": "0.10044235196789414",
        "dvc_data_version_info": {
            "field": "Feature",
            "filename": "feature_importance.csv",
            "revision": "exp-fe059"
        }

[pared]

@dberenbaum yep, hence the WIP, but I am not sure yet if we want to merge it, as I see that vscode team can handle that support even with existing DVC. Let's wait how the vscode implementation progresses, I can fix the tests when needed.

[pared]

Ok, as I see in https://github.com/iterative/vscode-dvc/issues/1757#issuecomment-1250230807 we do rely on it. I will update this PR

[mattseddon]

Minor comments. If it works for VSCode, lgtm

Everything seems to be working on our end 👍🏻.