[US]: Reset cancellation timeout to default value via CLI

[HaGGi13]

User Story Description

As a User, I want to remove a custom cancellation timeout configuration value, so that default value is used again instead.

Example
I imagine something like followed:

# ConnyConsole.exe config unset <configuration key>
> ConnyConsole.exe config unset Cancellation.Timeout

# This should print an error and/or help text
> ConnyConsole.exe config unset

Acceptance criteria

I see (that):

• Can reset the current applied cancellation timeout to its default value
• It's necessary to define the cancellation timeout setting key to reset the value
• Using a setting key with contained wildcard is not supported
• If no custom value was configured before, nothing is done/will be changed
• On execution the set value before reset and after reset is printed
• The output value is self-explaining, meaning it's obvious if it's unit is seconds, minutes etc.
• If no setting key was provided, an error and/or help text is printed instead

Remarks

It's expected that common CLI conventions are followed.