[9.x] Add supportsTemporaryUrl to FilesystemAdapter

[Jasonej]

This PR adds a supportsTemporaryUrl() method to FilesystemAdapter that checks if the adapter has getTemporaryUrl or a temporaryUrlCallback.

[taylorotwell]

Hi! What is this fixing or doing?

[Jasonej]

Hi, it's seeking to allow the following in situations where temp urls are preferred when supported, but are not required.

$filesystem = Storage::disk($disk);

$url = $filesystem->supportsTemporaryUrl()
    ? $filesystem->temporaryUrl($path, $expiration)
    : $filesystem->url($path);

Currently, the temporaryUrlCallback is not exposed as it is protected, so to accomplish this behavior the options are to assume that no callback exists and rely on a method_exists() check or do a try/catch that checks for the RuntimeException that is thrown by temporaryUrl().

[driesvints]

Renamed to ProvidesTemporaryUrls btw.