User error info and version check

[svartkanin]

• An error is now also written to the log file
• If an error happens, there will be a more user friendly addiction to it to guide the user on where to report it and how to extract the file from the ISO
• Version check when starting archinstall to show the user that an update is available - Fix Auto updating the script when the ISO boots #2148

[Torxed]

I like this a lot.
Note to the future, we should really start thinking about possibly using our own cache/db for archinstall related tasks.

There's two reasonings I find valid here:

1. This separates archinstall from the systems instance, meaning we can do pacman -Sy to get a fresh package list - but at the same time the user can outside of archinstall do pacman -S <package> and not get version conflicts.
2. When potentially using archinstall in the future to administrate package setups (lets say they want to post-install configure a desktop setup, that could become possible), then the same benefit from point 1 would apply :)

But this is a great enhancement, so lets get it in!