Ignore colors and formatting when determining string length.

Summary:
When calculating the length of a string with `phutil_utf8_console_strlen`, escape codes shouldn't contribute any width to the string.

This change allows for the widths of a `PhutilConsoleTable` table to be determined correctly when using rows containing formatting and/or colors.

Test Plan:
**Before**
{F167511}

**After**
{F167512}

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley, #blessed_reviewers

Subscribers: epriestley, Korvin

Differential Revision: https://secure.phabricator.com/D9597