Wasm demo release

Merge pull request #729 from pguyot/w31/monitor-posix_select-s

Add monitor to posix_select

Monitor selecting process to avoid leaks.
Add tests

These changes are made under both the "Apache 2.0" and the "GNU Lesser General
Public License 2.1 or later" license terms (dual license).

SPDX-License-Identifier: Apache-2.0 OR LGPL-2.1-or-later