zlib: use .bytesWritten instead of .bytesRead

The introduction of `.bytesRead` to zlib streams was unfortunate,
because other streams in Node.js core use the exact opposite naming
of `.bytesRead` and `.bytesWritten`.

While one could see how the original naming makes sense in
a `Transform` stream context, we should try to work towards more
consistent APIs in core for these things.

This introduces `zlib.bytesWritten` and documentation-only deprecates
`zlib.bytesRead`.

PR-URL: nodejs#19414
Refs: nodejs#8874
Refs: nodejs#13088
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Сковорода Никита Андреевич <chalkerx@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Sakthipriyan Vairamani <thechargingvolcano@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>

Author: addaleax

doc/api/deprecations.md

@@ -822,6 +822,16 @@ Type: Documentation-only (supports [`--pending-deprecation`][])
 Using `process.binding()` in general should be avoided. The type checking
 methods in particular can be replaced by using [`util.types`][].
 
+<a id="DEP0108"></a>
+### DEP0108: zlib.bytesRead
+
+Type: Documentation-only
+
+Deprecated alias for [`zlib.bytesWritten`][]. This original name was chosen
+because it also made sense to interpret the value as the number of bytes
+read by the engine, but is inconsistent with other streams in Node.js that
+expose values under these names.
+
 [`--pending-deprecation`]: cli.html#cli_pending_deprecation
 [`Buffer.allocUnsafeSlow(size)`]: buffer.html#buffer_class_method_buffer_allocunsafeslow_size
 [`Buffer.from(array)`]: buffer.html#buffer_class_method_buffer_from_array