Add a Utf16CharacterStream for windows-1252, which uses a table to
covert from windows-1252 to the appropriate uc16 character. This fixes
issues where windows-1252 encoded source was treated like latin-1.

This introduces a new encoding type in the API, so embedders will have
to opt-in to using this new stream.

Fixed: v8:9315
Change-Id: I2e847c2d4f1727281f6be24b4743d77bb232a62d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2729338
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Auto-Submit: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73134}