Map U+10DE to 3 when checking for confusables

Georgian letter U+10DE (პ) looks similar to the number 3. This cl adds
U+10DE to the mapping to 3 when determining whether to fall back to
punycode when displaying URLs.

Bug: 895207
Change-Id: I49713d7772428f8d364f371850a42913669acc4b
Reviewed-on: https://chromium-review.googlesource.com/c/1284396
Commit-Queue: Livvie Lin <livvielin@chromium.org>
Reviewed-by: Peter Kasting <pkasting@chromium.org>
Cr-Commit-Position: refs/heads/master@{#600193}