More error detail when read/write against remote cache fails

### Description of the feature request:

I was recently banging my head against trying to figure out why we were seeing intermittent 403 errors coming from our remote cache. Turns out it was due to an overzealous AWS WAF rule that was identifying some of the files we were trying to upload as malicious.

It would have been really convenient to have bazel spit out which files it was having issues with - it would have showcased the fact that in our particular case it was certain files that were always the problem, leading us to look into them in more depth.

### What underlying problem are you trying to solve with this feature?

Debugging remote cache failures

### Which operating system are you running Bazel on?

MacOS, Linux

### What is the output of `bazel info release`?

_No response_

### If `bazel info release` returns `development version` or `(@non-git)`, tell us how you built Bazel.

_No response_

### What's the output of `git remote get-url origin; git rev-parse master; git rev-parse HEAD` ?

_No response_

### Have you found anything relevant by searching the web?

_No response_

### Any other information, logs, or outputs that you want to share?

_No response_