Add libsoup.wrap and libpsl.wrap

libpsl is a dependency of libsoup that has an upstream meson build definition. The other 2 dependencies are xml2 and sqlite3 that still must come from the platform for now, but could be built from wrapdb once libsoup adds fallback for them.

This is enough to build souphttpsrc for the Android platform because xml2 and sqlite are already there (but not in NDK).