Support IPv6 addresses in debuggerAddress

Updates the host:port parsing logic in chromedriver so that the
debuggerAddress option can accept ipv6 addresses. This change does not
support ipv6 addresses containing a zone id as the underlying url
libraries will not parse them.

Bug: 1112509
Change-Id: I2adb13b5788fc88a5ce4c415f680e2e3f93d6c64
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2412811
Reviewed-by: Shengfa Lin <shengfa@google.com>
Commit-Queue: Satsuki Ueno <satsukiu@google.com>
Cr-Commit-Position: refs/heads/master@{#809024}