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, 3 insertions, 2 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 1176afee7..40d905791 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1913,6 +1913,7 @@ dependencies = [
  "rustls-tokio-stream",
  "rustls-webpki",
  "serde",
+ "tokio",
  "webpki-roots",
 ]
 
@@ -5457,9 +5458,9 @@ dependencies = [
 
 [[package]]
 name = "rustls-tokio-stream"
-version = "0.2.17"
+version = "0.2.23"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ded7a36e8ac05b8ada77a84c5ceec95361942ee9dedb60a82f93f788a791aae8"
+checksum = "c478c030dfd68498e6c59168d9eec4f8bead33152a5f3095ad4bdbdcea09d466"
 dependencies = [
  "futures",
  "rustls",