Use the new libxmlb prepared queries feature to make search faster

On ARM hardware this makes searches 76% faster.
1 job for <span class="ref-name">wip/hughsie/libxml-XbQuery</span> in 4 minutes and 48 seconds (queued for 3 seconds)
Status Job ID Name Coverage
  Build
passed #130963
build-gnome-software

00:04:48