[US]: Output current cancellation timeout configuration on CLI

[HaGGi13]

User Story Description

As a User, I want to get the current configured cancellation timeout output by using the CLI, so that I have not to search/check any configuration files.
If no custom configuration was defined, I expect to get the default value output instead. I also expect the output of the value that is actually used by the CLI.
If no configuration to fetch was defined, it's expected to get an error and/or help text printed.

Example
I imagine something like followed:

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

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

Acceptance criteria

I see (that):

• Can get the current applied cancellation timeout output by defined setting key
• Using a setting key with contained wildcard is not supported
• If no custom value was configured before, the default value is output
• Fetched value is output on console
• 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.