test: refactor test-debugger-remote

Checklist

• make -j4 test (UNIX), or vcbuild test (Windows) passes
• commit message follows commit guidelines

Affected core subsystem(s)

test

Description of change

1. The test doesn't attach an event listener for exit events and removes them before killing. The intention is to fail the tests if the processes exit normally. This patch attaches the exit event handlers.

2. Replace vars with lets and consts.

3. Replace == based assertion with strictEqual assertion.

4. Use common.PORT instead of 5959.

5. The test used to expect only one string "connecting to localhost:5959 ... ok", but the debugger actually emits another string, "break in test/fixtures/empty.js:2". This patch asserts if both of them are received in the same order.

Refer: https://github.com/nodejs/node/issues/10361