[ChromeVox] Add Launch Row for Event Log to New ChromeVox Settings Page

Inside the new ChromeVox settings page, add Launch Row for ChromeVox
Developer Event Log Page.

[This is an external page link, which opens the Log in a new window]
(Can also access via ChromeVox menu -> 'Open Developer Log Page', or
via 'Search + O', 'W')

Tested in Lacros - window opens in Ash via launch row and menu item.

Screenshot: https://screenshot.googleplex.com/8D9Jg9g8fJfmrSc

Bug: b/270617777
Change-Id: I052b7f78822676ab35f7c7bdb85fee20a1fcf87c
AX-Relnotes: N/A.
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4348041


Reviewed-by: Katie Dektar <katie@chromium.org>
Reviewed-by: Wes Okuhara <wesokuhara@google.com>
Commit-Queue: Josiah Krutz <josiahk@google.com>
Cr-Commit-Position: refs/heads/main@{#1118899}