[ie/youtube] Implement external n/sig solver (#14157)

Closes #14404, Closes #14431, Closes #14680, Closes #14707

Authored by: bashonly, coletdjnz, seproDev, Grub4K

Co-authored-by: coletdjnz <coletdjnz@protonmail.com>
Co-authored-by: bashonly <bashonly@protonmail.com>
Co-authored-by: sepro <sepro@sepr0.com>

yt_dlp/extractor/youtube/jsc/_builtin/node.py

@@ -0,0 +1,70 @@
+from __future__ import annotations
+
+import re
+import shlex
+import subprocess
+
+from yt_dlp.extractor.youtube.jsc._builtin.ejs import EJSBaseJCP
+from yt_dlp.extractor.youtube.jsc.provider import (
+    JsChallengeProvider,
+    JsChallengeProviderError,
+    JsChallengeRequest,
+    register_preference,
+    register_provider,
+)
+from yt_dlp.extractor.youtube.pot._provider import BuiltinIEContentProvider
+from yt_dlp.utils import Popen
+
+
+@register_provider
+class NodeJCP(EJSBaseJCP, BuiltinIEContentProvider):
+    PROVIDER_NAME = 'node'
+    JS_RUNTIME_NAME = 'node'
+
+    _ARGS = ['-']
+
+    def _run_js_runtime(self, stdin: str, /) -> str:
+        args = []
+
+        if self.ejs_setting('jitless', ['false']) != ['false']:
+            args.append('--v8-flags=--jitless')
+
+        # Node permission flag changed from experimental to stable in v23.5.0
+        if self.runtime_info.version_tuple < (23, 5, 0):
+            args.append('--experimental-permission')
+            args.append('--no-warnings=ExperimentalWarning')
+        else:
+            args.append('--permission')
+
+        cmd = [self.runtime_info.path, *args, *self._ARGS]
+        self.logger.debug(f'Running node: {shlex.join(cmd)}')
+        with Popen(
+            cmd,
+            text=True,
+            stdin=subprocess.PIPE,
+            stdout=subprocess.PIPE,
+            stderr=subprocess.PIPE,
+        ) as proc:
+            stdout, stderr = proc.communicate_or_kill(stdin)
+            stderr = self._clean_stderr(stderr)
+            if proc.returncode or stderr:
+                msg = f'Error running node process (returncode: {proc.returncode})'
+                if stderr:
+                    msg = f'{msg}: {stderr.strip()}'
+                raise JsChallengeProviderError(msg)
+
+        return stdout
+
+    def _clean_stderr(self, stderr):
+        return '\n'.join(
+            line for line in stderr.splitlines()
+            if not (
+                re.match(r'^\[stdin\]:', line)
+                or re.match(r'^var jsc', line)
+                or '(Use `node --trace-uncaught ...` to show where the exception was thrown)' == line
+                or re.match(r'^Node\.js v\d+\.\d+\.\d+$', line)))
+
+
+@register_preference(NodeJCP)
+def preference(provider: JsChallengeProvider, requests: list[JsChallengeRequest]) -> int:
+    return 900