Fix YAML validation in cell metadata

[cderv]

On windows, this does not fail and should

---
title: "YAML intelligence should fail with knitr engine"
---

```{r}
#| echo: 123
1 + 1
```

And possibly using more backtick should fail always, and it is not

---
title: "YAML intelligence should fail with knitr engine"
engine: julia
---

This code cell has more than default 3 backticks

````{julia}
#| echo: 123
1 + 1
````

[cderv]

@cscheid This PR also add some basic YAML validation for engine: julia doc. It seemed we did not have some, even basic.

@MichaelHatherly @jkrumbiegel Just a heads up that when this PR is merged, YAML option syntax in cell will be now validated

Document with non valid option like

---
title: "YAML intelligence should fail with knitr engine"
---
```{julia}
#| echo: 123
1 + 1
```

will now error.

Other engine have some specific schema tag that allows to filter out specific schema. Example

• tidy option is specific to knitr engine
  

  quarto-cli/src/resources/schema/cell-codeoutput.yml

  Lines 117 to 125 in 22b6c5d

  	- name: tidy
  	tags:
  	engine: knitr
  	schema:
  	anyOf:
  	- boolean
  	- enum: [styler, formatR]
  	default: false
  	description: "Whether to reformat R code."

• tags is specific to Jupyter engine
  

  quarto-cli/src/resources/schema/cell-attributes.yml

  Lines 13 to 18 in 22b6c5d

  	- name: tags
  	tags:
  	engine: jupyter
  	schema:
  	arrayOf: string
  	description: "Array of tags for notebook cell"

If there are some specific options to support, this needs to happen in those schema files - Open a PR and I'll help.

[MichaelHatherly]

Thanks for the heads up @cderv, there will be some that'll need to be added for QNR. I'll open a PR when I have a chance to.