Evaluate svelte-package and inlining styles

[theetrain]

Why

svelte-package helps convert component types and preprocessors into packaged components with separate type declarations files. With this tool, it may be possible to:

1. Write components in Typescript, and import Carbon Sass within <style lang="sass">
2. Have output component include separate .svelte and .svelte.d.ts files, and Sass styles be converted to scoped CSS

If proven successful, users of carbon-components-svelte should be able to import components without needing to manually import entire CSS themes, nor have to install Sass just to include component-specific styles. And they can add a global theme if they wish to use a theme other than the default (white).

Out of scope

• This is blocked by Carbon v11 style integration (component checklist) #1629.
• Add GlobalTheme chore: rename Theme to GlobalTheme #1702