Improve resiliency

Bug Fix

What does this MR do?

• Improves shell command resiliency by implementing unified error handling for all use cases and a timeout to not block other processes.
• Changes the default startup delay to 2 seconds. A lot of hardware prefers this and other similar programs set a high default.
• a few smaller refactorings and resiliency improvements
• keeps searching for a Xauthority file until it's found or it hits the timeout of 10 seconds. (Some systems take quite some time to produce this file)
• If no Xauthority file is found then Fan Control is disabled for Nvidia GPUs.
• Improved logging for Xauthority issues.

Related issues

Resolves #156 (closed)

Checklist

• Application works as expected when running from source
• There are dependency changes
• Liquidctl device mock tests are successful (if applicable)
• Any needed documentation changes have been made
• This MR is ready to be merged