fix: correctly match asset filenames if base path is set

[eltigerchino]

fixes #12060

Exports the base path of the project so we can remove the base path from the request URL pathname when matching against the static asset filenames in the manifest that are saved without the base path.

might add some tests later just because the path matching has proven to be error prone

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Latest commit: 38fcb8f

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 2 packages

Name	Type
@sveltejs/adapter-cloudflare-workers	Patch
@sveltejs/adapter-cloudflare	Patch

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