Add a container option to override the extension check and force a
container when saving.
Add some more formats that are supported by libsndfile.
Add some options to list all supported formats, extensions/containers,
layouts and channel names.
Fixes#5117
Use (fixed-up) Doxygen manpage output for all program & module manpages.
This also allows formatting the manual pages properly in the HTML docs.
The Markdown pages work properly only with Doxygen >= 1.9.7, older
versions put them to wrong place in the HTML docs.
