Improve `local_time` util

[doshitan]

local_time defaults to CST? Why? Should at minimum inherit from an app config item. User model should maybe have a preference field for timezone (and time/date format?).

Or just use https://github.com/basecamp/local_time

[MichaelCrawfordNava]

Per request to mention this here by @doshitan :

This PR was merged into community-engagement-medicaid, which allows setting the timezone within the application. The PR only affects conversion before using the datetime (such as after pulling the date/time from the database), but should affect storage of the date/time to the database or anything else.