Initially I considered updating the `NameOrNumberTree`-implementation to handle encoded keys, however that quickly became somewhat messy (especially in the `NameOrNumberTree.get`-method) since only NameTrees using string-keys.
Hence the easiest solution, as far as I'm concerned, was thus to just update the `Catalog.destinations`-getter instead. Please note that in the referenced PDF document the `Catalog.destination`-method will thus fallback to fetch all destinations, which should be fine since this is the very first case of encoded keys that we've seen.

Also changes the `NameOrNumberTree.getAll`-method to prevent a possible run-time error, although we've so far not seen such a case, for any non-Array Kids-entries found in a NameTree/NumberTree.

Finally, to improve overall consistency and to hopefully prevent future bugs, the patch also updates a couple of other `NameTree` call-sites to correctly handle encoded keys. (Note that the `Catalog.attachments`-getter was already doing this.)