feat!: correctly interpret /**/* paths

[Skn0tt]

This came up over in this forums post: https://answers.netlify.com/t/please-clarify-documentation-for-edge-functions-excludedpath/97443

Given the path /**/*.html, i'd expect it to match both /foo.html and /sub/foo.html. With our current handling, only /sub/foo.html is matched however - i've demonstrated this in a test added in the first commit of this PR.

After reading into this, it turns out that the special meaning of ** was introduced "recently" in 2010 and is called globstar. We don't have it enabled for edge functions currently, which means that /**/*.html is equivalent to /*/*.html. This probably comes at a surprise to our customers.

This PR enables the globstar option. This is a breaking change to what we implemented, and i'm unsure what's the best way of rolling this out. Here's a matrix for how it'd change behaviour:

	matched paths, currently	with globstar
/*.html	/foo.html, /sub/foo.html	/foo.html
/**/*.html	/sub/foo.html	/foo.html, /sub/foo.html

This would essentially break sites that have an edge function at /*, so i'm really unsure if this is a change we can make now 🤔 Let's have a discussion on that.

[Skn0tt]

closing in favor of #392