misc/xdelta3: Update to 3.2.0 and take maintainership

Port changes:

• Switch the upstream build from Autotools to CMake (see https://github.com/jmacd/xdelta)
• Update the declared license from GPLv2+ to Apache 2.0 (as per https://github.com/jmacd/xdelta)
• Enable armor support and the static-library build
• Install the public header, static library, pkg-config file, and CMake package metadata
• Remove the obsolete regtest patch (not required anymore due to changes to the build infrastructure)
• Update WWW, COMMENT, and pkg-descr to reflect these chagnes
• Add a complete pkg-plist

Changelog: https://github.com/jmacd/xdelta/releases/tag/v3.2.0

PR: 297302
Reported by: Thomas Barabosch <oss@tbarabosch.com> (new maintainer)
Reviewed by: diizzy