refactor(node): clean up debuglog

[kt3k]

part of #1707

This PR moves node/_util/_debuglog.ts to node/internal/util/debuglog.ts to align the directory structure to node.js code base. This PR also fixes the debug log output format. It reduces the duplicated new lines

Before

$ NODE_DEBUG=* node tls-server.js
NET 96541: 'setupListenHandle' null 8000 4 0 undefined

NET 96541: 'setupListenHandle: create a handle'

NET 96541: 'bind to' '::'

After

$ NODE_DEBUG=* node tls-server.js
NET 96541: 'setupListenHandle' null 8000 4 0 undefined
NET 96541: 'setupListenHandle: create a handle'
NET 96541: 'bind to' '::'

[bartlomieju]

LGTM