[https] Add highWaterMark to RequestOptions , Add agent.onKeylog event hander

app/current/src/main/scala/io/scalajs/nodejs/http/RequestOptions.scala

@@ -43,6 +43,7 @@ trait RequestOptions extends js.Object {
   var secureProtocol: js.UndefOr[String]                                   = js.undefined
   var sessionIdContext: js.UndefOr[String]                                 = js.undefined
   var insecureHTTPParser: js.UndefOr[Int]                                  = js.undefined
+  var highWaterMark: js.UndefOr[Int]                                       = js.undefined
 
   @enableIf(io.scalajs.nodejs.internal.CompilerSwitches.gteNodeJs14)
   var maxHeaderSize: js.UndefOr[Int] = js.undefined

app/current/src/main/scala/io/scalajs/nodejs/https/package.scala

@@ -1,5 +1,7 @@
 package io.scalajs.nodejs
 
+import com.thoughtworks.enableIf
+import io.scalajs.nodejs.buffer.Buffer
 import io.scalajs.nodejs.http.{RequestOptions, ServerResponse}
 import io.scalajs.util.PromiseHelper._
 import io.scalajs.nodejs.url.URL
@@ -54,4 +56,9 @@ package object https {
       promiseCallback1[ServerResponse](https.request(url, options, _))
     }
   }
+
+  implicit final class AgentExtensions[T <: Agent](private val instance: T) extends AnyVal {
+    @enableIf(io.scalajs.nodejs.internal.CompilerSwitches.gteNodeJs12)
+    @inline def onKeylog(handler: (Buffer, tls.TLSSocket) => Any): T = instance.on("keylog", handler)
+  }
 }