fig-cap-location margin support for Typst

[cderv]

---
format: 
  html: default
  typst: default
---

```{r}
#| label: fig-test
#| fig-cap: TEST
#| fig-cap-location: margin
plot(cars)
```

I think currently we don't support margin in typst format - article Layout for typst is still to support.

Though I believe we should have a failsafe and avoid bad error due to this missing support.

This is what we get currently,

typst]: Compiling test.typ to test.pdf...error: unknown variable: margin
    ┌─ \\?\C:\Users\chris\Documents\DEV_OTHER\00-TESTS\test-quarto\test.typ:282:10
    │
282 │ position: margin, 

because the fig-cap-location value is passed asis. We get this typ content for now

```r
plot(cars)
```

#figure([
#box(image("test_files/figure-typst/fig-test-1.svg"))
], caption: figure.caption(
position: margin, 
[
TEST
]), 
kind: "quarto-float-fig", 
supplement: "Figure", 
)
<fig-test>

Without cross-references, it just does not work without error

```{r}
#| fig-cap: TEST
#| fig-cap-location: margin
plot(cars)
```

(it is working for HTML - just ignored for Typst which seems ok for now. A warning could be added in typst format case to explain fig-cap-location is ignored)

So to sum up

• We should probably not error like this and just ignore the configuration for typst so that it renders but with a default
• We need to add support it - probably when we'll tackle article layout for typst format.

[cderv]

I saw now your comment, after preparing a PR for the first part of the sum up. No rendering error, and a warning, while using a fallback

[cscheid]

We fixed this in 1.5.

[cderv]

@cscheid FWIW I left this issue opened initially as a reminder to try add support for this layout in typst format.

Maybe this is not considered possible right now, but we are missing Article Layout for typst with margin content like LaTeX, so I thought we could keep it as a reminder