debugger: rename internal library for clarity

When I moved these files from node-inspect to Node.js core, I put them
in lib/internal/inspector. That was a mistake. They should be in
lib/internal/debugger.

PR-URL: nodejs#39080
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>

lib/internal/inspector/_inspect.js → lib/internal/debugger/_inspect.js

@@ -31,8 +31,8 @@ const util = require('util');
 
 const { 0: InspectClient, 1: createRepl } =
     [
-      require('internal/inspector/inspect_client'),
-      require('internal/inspector/inspect_repl'),
+      require('internal/debugger/inspect_client'),
+      require('internal/debugger/inspect_repl'),
     ];
 
 const debuglog = util.debuglog('inspect');

lib/internal/main/inspect.js

@@ -18,5 +18,5 @@ markBootstrapComplete();
 
 // Start the debugger agent.
 process.nextTick(() => {
-  require('internal/inspector/_inspect').start();
+  require('internal/debugger/_inspect').start();
 });

node.gyp

@@ -125,6 +125,9 @@
       'lib/internal/crypto/sig.js',
       'lib/internal/crypto/util.js',
       'lib/internal/constants.js',
+      'lib/internal/debugger/_inspect.js',
+      'lib/internal/debugger/inspect_client.js',
+      'lib/internal/debugger/inspect_repl.js',
       'lib/internal/dgram.js',
       'lib/internal/dns/promises.js',
       'lib/internal/dns/utils.js',
@@ -148,9 +151,6 @@
       'lib/internal/heap_utils.js',
       'lib/internal/histogram.js',
       'lib/internal/idna.js',
-      'lib/internal/inspector/_inspect.js',
-      'lib/internal/inspector/inspect_client.js',
-      'lib/internal/inspector/inspect_repl.js',
       'lib/internal/inspector_async_hook.js',
       'lib/internal/js_stream_socket.js',
       'lib/internal/linkedlist.js',