[roll] Roll fuchsia [sestarnix] Unify policy object ID types

Unify UserId, RoleId, ClassId, ClassPermissionId, and AccessVector to
use the type-safe IdType wrapper (or new_policy equivalents), matching
the existing unification of TypeId. This provides type safety and
consistency across all policy object identifiers.

Specifically:
- UserId, RoleId, and ClassId are now type aliases to IdType.
- The redundant ClassPermissionId struct is removed in favor of
  PermissionId (IdType).
- AccessVector is unified with the new parser's implementation.
- All call-sites are updated to use from_u32() / for_test() and
  as_u32() / u32::from() instead of tuple struct constructors and
  .0 accessors.

This is a pure refactoring change to simplify review before introducing
classes and constraints parsing. It does not introduce any new parsing
logic.

Original-Original-Bug: 527401888
Test: fx test starnix-selinux-unit-tests
TAG: agy
CONV: a4f3c876-713c-4cce-b711-d02b2a6c035f
Original-Original-Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/1687456
Original-Original-Revision: 97f693516bc6bc9e0af19459e96286b3e53f12f9
GitOrigin-RevId: d3e281087e3852759ca72b185ddd891dcfb339e0
Change-Id: I250b784c545609d7cb649924b06246e26d2c7d6d
Reviewed-on: https://fuchsia-review.googlesource.com/c/integration/+/1692165
Cr-Commit-Position: refs/heads/main@{#196102}