[storage-js] Skip `.from('bucket')` storage calls syntax for `createSignedUrls` function

Hello, the current syntax to get a batch of signedUrls assumes all the paths of the array of files are in the same bucket. We query our files for a user and said files are stored in different buckets. I understand that for single files the .from()... syntax may be easier to read, but for batch processes it forces us to run multiple API calls to the storage API to generate the signed URLs, once for each set of files for a bucket. This pattern so far affects this call, but could potentially impose this limit on other functionality as well.

One solution is for the batch process, skipping the from part and pass the complete file path (including the bucket) in the array of files.