fix: graceful exit using ctrl+C if not test are running

[guerinoni]

This will return exit code 0 if gotestsum is waiting for any changes and
it is interrupted, otherwise if some tests are running using ctrl+c it
interrupts the tests and exit with status 1.

The refactoring here is for using a single context and propagate over the other processes/functions.

This way is more clear where we cancel and what we do in sub-fuction at the moment of finishing the context.

No double signlar handlers are created.

Closes #508

[dnephin]

Thank you for the PR!

There's already a signal handler added in newSignalHandler. That forwards signals to tests so that the first Ctrl-c cancels the tests instead of exiting gotestsum.

I think this will need to integrate with that function somehow.

[guerinoni]

Thank you for the PR!

There's already a signal handler added in newSignalHandler. That forwards signals to tests so that the first Ctrl-c cancels the tests instead of exiting gotestsum.

I think this will need to integrate with that function somehow.

I managed to use same context as a starting point, and later other ctx are created starting from that, it seems good now

[guerinoni]

@ccoVeille i kept the interface, it is super useful in testing, I added a comment to explicty say this :D

[guerinoni]

@dnephin if you have other concerns let me know :D

[guerinoni]

@ccoVeille do you think i need other changes here?

[ccoVeille]

Nope, the PR is fine and could be merged by a maintainer according to me.