stream: implement TextEncoderStream and TextDecoderStream

Experimental as part of the web streams implementation

Signed-off-by: James M Snell <jasnell@gmail.com>

PR-URL: https://github.com/nodejs/node/pull/39347
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>

tools/doc/type-parser.mjs

@@ -253,6 +253,10 @@ const customTypesMap = {
     'webstreams.md#webstreamsapi_class_bytelengthqueuingstrategy',
   'CountQueuingStrategy':
     'webstreams.md#webstreamsapi_class_countqueuingstrategy',
+  'TextEncoderStream':
+    'webstreams.md#webstreamsapi_class_textencoderstream',
+  'TextDecoderStream':
+    'webstreams.md#webstreamsapi_class_textdecoderstream',
 };
 
 const arrayPart = /(?:\[])+$/;