refactor(ext/tls): Implement required functionality for later SNI support (#23686)

Precursor to #23236 

This implements the SNI features, but uses private symbols to avoid
exposing the functionality at this time. Note that to properly test this
feature, we need to add a way for `connectTls` to specify a hostname.
This is something that should be pushed into that API at a later time as
well.

```ts
Deno.test(
  { permissions: { net: true, read: true } },
  async function listenResolver() {
    let sniRequests = [];
    const listener = Deno.listenTls({
      hostname: "localhost",
      port: 0,
      [resolverSymbol]: (sni: string) => {
        sniRequests.push(sni);
        return {
          cert,
          key,
        };
      },
    });

    {
      const conn = await Deno.connectTls({
        hostname: "localhost",
        [serverNameSymbol]: "server-1",
        port: listener.addr.port,
      });
      const [_handshake, serverConn] = await Promise.all([
        conn.handshake(),
        listener.accept(),
      ]);
      conn.close();
      serverConn.close();
    }

    {
      const conn = await Deno.connectTls({
        hostname: "localhost",
        [serverNameSymbol]: "server-2",
        port: listener.addr.port,
      });
      const [_handshake, serverConn] = await Promise.all([
        conn.handshake(),
        listener.accept(),
      ]);
      conn.close();
      serverConn.close();
    }

    assertEquals(sniRequests, ["server-1", "server-2"]);
    listener.close();
  },
);
```

---------

Signed-off-by: Matt Mastracci <matthew@mastracci.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/runtime/worker.rs b/runtime/worker.rs
index a5fec16e4..1c291c641 100644
--- a/runtime/worker.rs
+++ b/runtime/worker.rs
@@ -39,6 +39,7 @@ use deno_http::DefaultHttpPropertyExtractor;
 use deno_io::Stdio;
 use deno_kv::dynamic::MultiBackendDbHandler;
 use deno_tls::RootCertStoreProvider;
+use deno_tls::TlsKeys;
 use deno_web::BlobStore;
 use log::debug;
 
@@ -450,7 +451,7 @@ impl MainWorker {
             unsafely_ignore_certificate_errors: options
               .unsafely_ignore_certificate_errors
               .clone(),
-            client_cert_chain_and_key: None,
+            client_cert_chain_and_key: TlsKeys::Null,
             proxy: None,
           },
         ),