[shared storage] Implement sharedStorage.batchUpdate() for PA worklet

Add sharedStorage.batchUpdate() function. Parse arguments into
the 'methods' sequence and a 'with_lock' optional flag, and
propagate the result to the browser process to invoke the
`SharedStorageLockManager::SharedStorageBatchUpdate()` API.

This allows developers to perform multiple Shared Storage operations atomically within a single lock, as part of the Web
Lock integration proposal:
- https://github.com/WICG/shared-storage/pull/199
- https://github.com/WICG/shared-storage/pull/205

Fuchsia-Binary-Size: Size increase is unavoidable.
Bug: 373899210
Change-Id: Ic6e9f794d78523ec9f6b87f37fb5e91f17635c58
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6072850
Commit-Queue: Yao Xiao <yaoxia@chromium.org>
Reviewed-by: Maks Orlovich <morlovich@chromium.org>
Reviewed-by: Cammie Smith Barnes <cammie@chromium.org>
Reviewed-by: Giovanni Ortuno Urquidi <ortuno@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1401673}