test: workaround for V8 8.1 inspector pause issue

`test-inspector-multisession-ws` and `test-inspector-break-when-eval`
will be affected by an upstream bug when we upgrade V8 to 8.1. The bug
is caused when the Inspector sets a pause at the start of a function
compiled with `CompileFunctionInContext`, but that function hasn't been
executed yet.

On both tests, this issue is triggered by pausing while in C++ executing
LookupAndCompile, which is called by requiring internal modules while
running `console.log`. To eliminate this issue in both tests, we add an
extra `console.log` to ensure we only pause we required all internal
modules we need. On `test-inspector-break-when-eval`, we also need to
start the child process with `--inspect-brk` instead of `--inspect` to
ensure the test is predictable (this test would occasianlly fail on
slower machines, when console.log doesn't run fast enough to finish
after emitting `Runtime.consoleAPICalled` and before the parent process
sending `Runtime.evaluate` message.

Ref...