rctx.download_and_extract should fully unpack .deb files

### Description of the feature request:

Currently, `rctx.download_and_extract` just extracts .deb files into its internals, e.g. `data.tar`, `control.tar`. It'd probably be more useful if it could actually extract the real data under it, like `dpkg -x` would do.

### Which category does this issue belong to?

Core

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

Easily unpack .deb files.

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

Ubuntu 24.04

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

release 7.3.1

### 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 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_

Start by locating the implementation of rctx.download_and_extract and inspect how it currently handles .deb archives, including data.tar and control.tar. Compare the desired behavior with dpkg -x and add or update coverage so the real package contents are unpacked rather than only the inner archives.

Written by the indexing model from the issue text.