Draft: Enable JSON charts in markdown (GLFM)

What does this MR do and why?

Along the same lines as our JSON Tables, this MR adds the ability to embed charts driven by JSON data. The intent is to support basically the same json structure as our GitLab UI chart components, such as https://design.gitlab.com/storybook/?path=/docs/charts-line-chart--docs

Here's an example line chart

```json:chart
{
  "type" : "line",
  "data" : [
    {"name" : "First Series",
     "data" : [
       ["Mon",1220],["Tue",932],["Wed",901],["Thu",934],["Fri",1290],["Sat",1330],["Sun",1320]
     ]
    },
    {"name" : "Second Series",
     "data" : [
       ["Mon",122],["Tue",93],["Wed",90],["Thu",94],["Fri",129],["Sat",133],["Sun",132]
     ]
    }
  ],
  "option": {"xAxis":{"name":"Time","type":"category"}}
```

which would get rendered as

Note

Markdown is NOT handled in the data, although it is in JsonTableFilter. It's a trickier problem and can be addressed in another iteration should the strong need arise.

How to set up and validate locally

MR acceptance checklist

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Related to Markdown charts (#25516)