chore: migrate to shiki for syntax highlighting

[techfg]

What does this PR do?

react-syntax-highlighter has some vulnerabilities based on its use of an outdated prismjs and refractor (which uses prismjs). It no longer appears that react-syntax-highlighter is being maintained so its time for a new syntax highlighter.

There are several options out there but shiki appears to be the library that many are moving towards. Upon review, it provides several benefits for us with only main con:

1. Pro: Feature parity with react-syntax-highlighter
2. Pro: Integration with monaco-editor to allow us to have consistent theming for both code blocks and monaco editor
3. Pro: Robust support for different themes, languages, etc.
4. Pro: TextMate grammar powered, same engine as VS Code
5. Con: Increases our bundle size for io package (raw: ~450k to ~1000k / gzip: ~148k to ~240k)

Given the gzip impact is small enough, this PR:

1. migrates to shiki, removing react-syntax-highlighter
2. fully supports js/ts/css/json/yaml/css syntax highlighting in markdown/code components (previously we only supported js/ts/yaml
3. adds line number support in markdown & code component
4. adds syntax highlighting to inline code blocks (previously we did not support this)
5. uses same themes in monaco/markdown/code components
6. improves legibility of monaco code view (was very difficult to discern yaml highlighting previously)
7. eliminates the prismjs vulnerability

Testing

Manual testing confirms, ci & e2e will cover rest.

Before Markdown Component

After Markdown Component

Before Code Panel

After Code Panel