Feature Request: KBFS File/Folder Caching w/ Background Updates

Navigating through kbfs can be quite slow at times. Every time you go up or down the tree one has to wait to retrieve the file listing, over and over again.

Could we not cache the results (files/folders) and fetch updates in the background? I don't see many people using kbfs for high-speed storage scenarios but we would all like to access what is there smoothly and quickly. Folders with a few hundred files, even small ones, can take up to 30 seconds to load (just the listing) even on a high speed connection.

Specifically I'm referring to file/folder listings (meta) not the files themselves.

The issue targets KBFS file and folder listings (metadata), not file contents. No files, tests, or entry points are named, so first locate the listing path and establish a baseline for folders with hundreds of files. Done means cached listings load smoothly while updates are fetched in the background.

Written by the indexing model from the issue text.