Cache terminal width
Summary: This maybe fixes T8576. Whilst running ./bin/search index --all I noticed that I ended up with 159,596 temporary directory which I believe are due to phutil_console_get_terminal_width() running too often.
Test Plan: N/A
Reviewers: epriestley, Blessed Reviewers
Reviewed By: epriestley, Blessed Reviewers
Subscribers: epriestley, Korvin
Maniphest Tasks: T8576
Differential Revision: https://secure.phabricator.com/D13519