Implement node.patchAll()

patchAll creates a writable stream that parses HTML, and applies patches
from <template patchfor> elements as they are discovered. Content
outside of patches is discarded.

This reuses some of the infrastucture from node.patchSelf, and parses
the HTML into a detached template element, rerouting patches into the
target.

Bug: 431374376
Change-Id: I3d6aa3bf46dd512bad67fe8e679ce80f9134db00
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6779124
Reviewed-by: Philip Jägenstedt <foolip@chromium.org>
Commit-Queue: Noam Rosenthal <nrosenthal@google.com>
Cr-Commit-Position: refs/heads/main@{#1491352}