adds the creation of Sentry CLI config files to the SvelteKit SDK setup

Add basic SDK setup code generation to the wizard. 

During SDK setup, we distinguish between two cases for each SvelteKit (client and server) hook file:
* If no hook file exists, we can just copy our hooks file template with the complete instrumentation. Great! 🎉
* If there is a pre-existing hooks file, we partially merge it with a Sentry import and init call and request additional manual intervention from the user

To respect custom hooks file locations that users can specifiy in `svelte.config.js`, we import the svelte config and use these custom paths if they're available. Otherwise, we fall back to the default paths.

…#257)

Replace the "old" init call injection approach with using magicast to modify the file

…oks (#259)

Add our handlers to the `handle` and `handleError` hooks in the SveltKit hooks files. Uses magicast and advanced AST manipulation to merge user-defined handlers with ours.

Converts the CLI appearance to use the `clack` library. Rewriting the flow to the new NextJS wizard flow.