net/xrdp: Update to 0.9.8

Also, update audio/pulseaudio-module to the latest release 0.2.
pulseaudio-module-xrdp 0.2 no longer have build time dependency on xrdp.
Accordingly, add runtime dependency on pulseaudio-module-xrdp to xrdp to
enable audio redirection by default it doesn't cause circular dependency
now.

While here,

• Pet portlint
• Switch PORTVERSION to DISTVERSION

Approved by: pi (mentor)
Relnotes: https://github.com/neutrinolabs/xrdp/releases/tag/v0.9.8
Sponsored by: HAW International, Inc.
Differential Revision: https://reviews.freebsd.org/D17326