`@action/glob`: expose a public method to test patterns on given paths

[redsun82]

Describe the enhancement
The globber instance returned by glob.create should have a method test(path: string): boolean returning whether the given path matches the patterns provided on creation.

Additional information
Currently @actions/glob only allows to use a pattern to iterate through actual files existing on the runner at the time of execution. There are however use cases where we want to know which files from a given list match against a list of patterns.

We have such a use case where we first fetch the list of files changed by a PR (via a paginated oktokit's rest.pulls.listFiles request), and we want to filter them with a list of patterns, in a way consistent with how glob patterns work across github actions.

@actions/glob would seem like the library of choice for this, but because it insists on providing existing files it's not of immediate use. I ended up recreating a tree structure of empty files from the list of modified files to appease @actions/glob, but a test method would be much more natural to use. As far as I can tell this would just require exporting functionality that is already present in the library implementation.