[roll] Roll fuchsia [build] Add script to verify ELF binaries in packages.

This CL adds a script to verify the ELF binaries inside a Fuchsia
package or system image. As such, it is called both from
fuchsia_package() and generate_manifest().

Its purpose is to verify that:

- Every executable binary has all its dependency libraries
  in the same package, either under lib/ or lib/<variant>/
  in the case of instrumented builds. This supports putting
  binaries built with distinct variants in the same package
  or system image.

- Each ELF binary is properly stripped (unless under /data/)

- For system images only, verify that each ELF binary has
  a corresponding debug file provded in the build system.
  This is currently disabled for fuchsia_package() because
  our Go-compiled binaries do not have debug information.
  This also happens with prebuilt driver binaries.

Note that for Fuchsia packages, this can be disabled by setting
'disable_elf_binaries_checks = true' when calling fuchsia_package()
or fuchsia_package_with_single_component(). This is necessary
for the android_starnix package for example, which embeds
non-Fuchsia binaries (some of them unstripped).

This mirrors most of the features of finalize_manifests.py, except
for its automatic stripping of ELF binaries, which is required
when using a custom clang or rust toolchain. A future CL will
address this specific point.

+ Fix the icd_strip test package to use the new
  fuchsia_test_package() template, and to always put the
  ICD library under lib/, even when it was built with
  a variant toolchain. This allows simplifying the test's
  logic to not depend on implementation details of our
  dynamic loader / build system.

+ Fix the src/media/lib/ffmpeg/BUILD.gn file to install
  the prebuilt libffmpeg.so to the right location when building
  with an instrumented variant. Before that, it was always
  installed as lib/libffmpeg.so, but the bin/mediaplayer
  program would try to find it from lib/asan/libffmpeg.so
  instead.

Original-Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/495961
Original-Revision: 3b0093820f624f973165a8c039554bfb4f626ea8
GitOrigin-RevId: 30013adf4d312e6b51bbded10cefead51ddf7021
Change-Id: I11a1ac0254676096284af633f96279082aab2add