[roll] Roll fuchsia [build][bazel] Generate proper depfile for bazel_action() targets.

This is a reland of [1] which was incorrectly reverted, since it
turned out that the root cause for the Ninja no-op failures was
different.

The main ideas behind this CL are:

- The bazel_action.py script, uses Bazel queries to determine
  the list of implicit inputs from a top-level Bazel target,
  which include both source files and build files.

- Input files that belong to Bazel external repositories must
  be mapped to locations outside of the Bazel output_base,
  the logic to do so is detailed in a long technical note
  in bazel_action.py and is ... sophisticated.

- update-workspace.py is updated to generate content hash
  files for many Bazel repositories. This was already the
  case for @fuchsia_sdk and @internal_sdk, but now there
  are also files for @fuchsia_clang, @prebuilt_clang,
  @com_google_googletest as well, and all files are now
  located under
  $BAZEL_TOPDIR/workspace/generated_repository_hashes/<repo_name>.hash

- Repository rules are updated to track said hash content
  files (by calling repository_ctx.path(), which is enough
  to force Bazel to record the association).

+ Remove `--bazel-platforms` option from bazel_action.py, just pass
  a `--platforms=<name>` extra Bazel argument instead.

+ Add @com_google_absl as local repository, as a transitive
  dependency of @com_google_googletest (required to avoid
  errors in Bazel queries).

Original-Bug: 117818

[1] https://fuchsia-review.googlesource.com/c/fuchsia/+/798682

NO_IFTTT=multiple_files_associated_with_single_change

Original-Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/808832
Original-Revision: 29c62fe2a43aa990fb49d3f18da207f1b975d28d
GitOrigin-RevId: 72747ecf542044d071b86e32527184d64f5c3608
Change-Id: I8ce7221413f4418a795da7a48d80caf4a107b3ed