Port HashPasswordManager to os_crypt async

This change replaces usage of OSCrypt::{Encrypt,Decrypt}String in
hash_password_manager.cc with async equivalents, so HashPasswordManager
now takes an os_crypt_async::Encryptor which must be plumbed through
everywhere it's used, which is in 3 places:

ChromePasswordProtectionService
- Pass HashPasswordManager as arguments since the only usage is in
  methods that are called from others that already have a
  HashPasswordManager available.
- Init is now async. This is safe because Init only does the following:
  1. Create a delayed task. This is already async.
  2. Set sync_password_hash_, which is strictly used only after
     HashPasswordManager is initialized.

PasswordReuseManagerImpl
- All methods on this class used externally (either public or via
  an interface or callback) return void, so this makes it possible to
  queue up tasks while waiting for OSCryptAsync.

SafeBrowsingUIHandler
- The task is already async, so the new async operation is an extra
  step of the existing task.

Bug: 447372315
Change-Id: I7fdbe1c9ad86d1667fd2a746d314cd792eb44243
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6974947
Reviewed-by: Vasilii Sukhanov <vasilii@chromium.org>
Commit-Queue: Thomas Anderson <thomasanderson@chromium.org>
Reviewed-by: Nathan Parker <nparker@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>
Reviewed-by: Peter Beverloo <peter@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1522447}