Use timedatectl to modify system time zone

Created by: SunilMohanAdapa

Currently, we have a bunch of code to list timezones and set timezone. Problems:

• This code is manually parsing timezone db.
• The timezone db we are parsing is a deprecated one (based on the warning at the time).
• Setting timezone has issues #554 (closed) .
• Is not future proof.
• Possibly is Debian specific.
• Had many issues in the past.

Use timedatectl instead. This will remove custom code and makes it easier. timedatectl list-timezones gives the list of timezones. This can be executed as non root user directly from the form. timedatectl set-timezone TIMEZONE will set the timezone. This needs to be executed as root user and requires the actions/datetime script. While we are at it, convert the actions/datetime module to Python.