cerbero: add assert and checks variants

• Added new assert variant, enabled by default, when disabled using noassert:
  • glib and all GStreamer recipes are configured with -Dglib_assert=false
  • all Meson projects are configured with -Db_ndebug=true
  • all cargo recipes are configured with the debug-assertions=false configuration argument
• Added new checks variant, enabled by default, when disabled using nochecks:
  • glib and all GStreamer recipes are configured with -Dglib_checks=false
  • all cargo recipes are configured with the overflow-checks=false configuration argument
• Added a patch from this libnice MR that adds support for the glib_debug, glib_assert, and glib_checks and updated the recipe to set the glib_assert and glib_checks values appropriately