Gracefully exit login and publish commands on Ctrl+C (SIGINT) in the new webAuthn flow

[neeldani]

What / Why

This PR resolves the bug which did not allow users to exit the CLI process on hitting CTRL + C for npm publish --auth-type=web and npm login auth-type=web commands.

Approach

We use readline to prompt the user to hit ENTER. However, the first time the user hits CTRL+C, it closes the readline instance (docs). The second CTRL+C then kills the CLI process. This PR adds an event listener which listens to readline's SIGINT event (docs) and then gracefully kills the CLI process from the cb function.

Note: The experience shown after hitting CTRL+C is kept similar to the existing experience when the user hits CTRL+C for login and publish commands without the auth-type=web flag

The PR also adds a test case to validate the same.

Experience

Login

login-sigint.mov

Publish

publish-sigint.mov

References

Resolves #5231

[npm-cli-bot]

no statistically significant performance changes detected

timing results

app-large	clean	lock-only	cache-only	cache-only peer-deps	modules-only	no-lock	no-cache	no-modules	no-clean	no-clean audit
npm@8	35.161 ±2.05	15.075 ±0.04	13.809 ±0.22	15.954 ±0.80	2.427 ±0.00	2.422 ±0.01	1.985 ±0.00	9.434 ±0.06	1.965 ±0.02	3.467 ±0.63
#5243	35.449 ±2.44	15.119 ±0.02	13.797 ±0.18	15.923 ±0.58	2.478 ±0.03	2.480 ±0.07	1.997 ±0.03	9.417 ±0.01	1.976 ±0.00	3.051 ±0.12

app-medium	clean	lock-only	cache-only	cache-only peer-deps	modules-only	no-lock	no-cache	no-modules	no-clean	no-clean audit
npm@8	24.653 ±0.25	11.584 ±0.08	10.232 ±0.07	11.110 ±0.50	2.286 ±0.05	2.246 ±0.02	2.016 ±0.01	6.996 ±0.06	1.919 ±0.02	2.636 ±0.01
#5243	25.698 ±0.16	11.757 ±0.01	10.339 ±0.05	11.436 ±0.61	2.269 ±0.00	2.249 ±0.03	2.044 ±0.03	7.006 ±0.10	1.913 ±0.01	2.651 ±0.01