[7.x] Fix issue where Storage::path breaks when using cache due to missing method in CachedAdapter

[rezen]

PR title sums everything up simply.

[GrahamCampbell]

I don't think this should be fixed here. The cached adapter needs to be updated?

[rezen]

@GrahamCampbell I had considered that, but decided against that for a couple reasons

• The pattern if ($adapter instanceof CachedAdapter) { is already in place (used 3 times)
• Implementing at the FilesystemAdapter is more stable than updating the dependency which may introduce other breakages.

[rezen]

I should additionally add, the Filesystem contract does not include path