Switch command, language support, bugfixes

Changelog:

• Added switch command: Allows you to switch between config files for different instances
  • (Currently only works for configs in the same folder)
• Added more cases for exiting after submission (Thanks @marfavi!)
• Added Rust support
• Added Go support
• Fixed Rust support
• Fixed lack of feedback when problem is already active with get command
• Fixed autocomplete for problem names on Windows (Thanks @Jakobis!)
• Bumped packages (Thanks @Jakobis!)

Open File Command

Changelog:

• Made the config make use of the openfilecommand option under [kat]. When defined, get command automatically invokes this function in order to open the problem in your editor of choice.
  I use Visual Studio Code, and thus my command is code -r @d, which opens the problem source file in my currently open editor. An alternative would be code @p if you want to open the problem folder.
• Made .out files work like .ans files
• Fixed boilterplate not getting copied
• Removed the stacktrace from terminating tests with ctrl+c
• Added feedback to contest get for when the contest hasn't begun
  • Also added feedback for when it is over.

On an organizational note:
I think I'll start using releases as a way to keep info about changes in this form instead of in commit history, which only I really look at.