Replace libxmljs2 with libxmljs as its no longer maintained

[devtobi]

Is your feature request related to a problem? Please describe.

Currently libxmljs2 is defined as an optionalDependency inside package.json.
Since the dependency is no longer maintained and only has supply chain risks due to native code being executed on postinstall hooks I recommend to replace it with the original now maintained libxmljs

See https://socket.dev/npm/package/libxmljs2

Describe the solution you'd like

Replace dependency inpackage.json and and fix references in demo and test.

Additional context

Contribution

• I am willing to provide an implementation
• I will wait until somebody else implements it

[devtobi]

Looks like we'd need a new release of libxmljs first (1.0.12 is currently in the making) to get rid of the CVEs. (see libxmljs/libxmljs#672)