net: Validate port in createServer().listen()

Pull Request check-list

• Does make -j8 test (UNIX) or vcbuild test nosign (Windows) pass with this change (including linting)?
• Is the commit message formatted according to [CONTRIBUTING.md][0]?
• If this change fixes a bug (or a performance problem), is a regression test (or a benchmark) included?
• Is a documentation update included (if this change modifies existing APIs, or introduces new ones)?

Affected core subsystem(s)

net

Description of change

Make sure we validate the port number in all kinds of listen() calls.

Fixes: #5727 (closed)