allow the user to specify the bucket name when using S3 and S3 compatible shortcuts when you don't have list buckets privilege

[mdjouallah1]

currently in order to use Cloudflare R2 or S3, you need to have permission to list all buckets, which can be very problematic. as list buckets is a high privilege and in a lot of scenarios, all you get is a bucket specific token, my request is to have the option to define a bucket name in the UI, so bucket scoped authentication works with shortcuts.

[Felipe_Assis]

We also ran into a scenario where this capability would be life-saving. The S3 was owned by a partner who host logs for a multi-tenant solution, so we only had access to a specific folder inside of it. If we could provide the path where we want to read data from and not having to rely on bucket-level permissions, we could have used shortcuts for this process.