Terminate Caliper workers on interrupting Caliper manager

[CaptainIRS]

In this PR:

• The SIGINT signal is handled in the manager to cleanly terminate workers when user tries to terminate Caliper manager.

Fixes #1361

[codecov[bot]]

Codecov Report

Attention: 5 lines in your changes are missing coverage. Please review.

Comparison is base (64f3868) 55.56% compared to head (541f2ab) 56.09%. Report is 15 commits behind head on main.

Files	Patch %	Lines
...re/lib/manager/orchestrators/round-orchestrator.js	0.00%	3 Missing :warning:
...ackages/caliper-core/lib/manager/caliper-engine.js	0.00%	1 Missing and 1 partial :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #1435 +/- ## ========================================== + Coverage 55.56% 56.09% +0.53% ========================================== Files 103 105 +2 Lines 4451 4539 +88 Branches 676 697 +21 ========================================== + Hits 2473 2546 +73 - Misses 1435 1438 +3 - Partials 543 555 +12 ``` | [Flag](https://app.codecov.io/gh/hyperledger/caliper/pull/1435/flags?src=pr&el=flags&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=hyperledger) | Coverage Δ | | |---|---|---| | [caliper-core](https://app.codecov.io/gh/hyperledger/caliper/pull/1435/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=hyperledger) | `45.38% <0.00%> (+1.07%)` | :arrow_up: | | [caliper-fabric](https://app.codecov.io/gh/hyperledger/caliper/pull/1435/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=hyperledger) | `80.46% <ø> (ø)` | | | [generator-caliper](https://app.codecov.io/gh/hyperledger/caliper/pull/1435/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=hyperledger) | `83.62% <ø> (ø)` | | Flags with carried forward coverage won't be shown. [Click here](https://docs.codecov.io/docs/carryforward-flags?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=hyperledger#carryforward-flags-in-the-pull-request-comment) to find out more.

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[stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[davidkel]

Closing as DCO is proving to be an issue. Replicated this PR in #1514