[ticket/16649] Add compiler pass to make all services public

This also handles BC for phpBB extensions

PHPBB3-16639

tests/functional/fixtures/ext/foo/bar/config/services.yml

@@ -1,5 +1,4 @@
 services:
-    _defaults: { public: true }
     foo_bar.controller:
         class: foo\bar\controller\controller
         arguments:

tests/functional/fixtures/ext/foo/foo/config/services.yml

@@ -1,4 +1,3 @@
 services:
-    _defaults: { public: true }
     foo_foo.controller:
         class: foo\foo\controller\controller