`"container"` sizing does not work

[sarah37]

It should be possible to set

"height": "container",
"width": "container"

in the spec and have the chart adapt to the surrounding container. This does not seem to work with <VegaLite /> (it works when using svelte-embed directly, but that's inconvenient in other ways, I haven't checked <Vega />).

Here's a Svelte Playground with a simple example: https://svelte.dev/playground/d720cdd6a76741b6848267361acbc562?version=latest