Fix some unused imports cases

[unlocomqx]

This is a simplification of the SvelteReferencesSearch class, it solves more unused imports cases, maybe all Basically, it enlarges the search scope from the script to the entire file

Current

Improvement

This can probably be done using <resolveScopeEnlarger/> but I'm not sure

[unlocomqx]

Oops, looks like we've been working on the same exact thing lol i'll close this one then

[tomblachut]

At least we have double-confirmation about direction being correct :P I wanted to do some tests around #146 first, merge that and release next version with improved import support