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