First PR for #40232.
Implement the getSecurityInfo protocol message to allow DevTools clients
to inspect TLS connection details for HTTPS requests, including:
- Protocol version (TLS 1.2/1.3)
- Cipher suite
- Key exchange group
- ALPN protocol
- HSTS and ECH status
- Security state
Security state is simplified (secure/insecure only) and certificate
details are stubbed out; both will be completed in follow-up work.
Signed-off-by: jiang1997 <jieke@live.cn>