Move FCI tests to extensions and attach oncall (5 / n)

Summary: Moves fci tests  from `hphp/facebook/test/ext/` to `hphp/facebook/extensions/fci/test/`. This will help decouple tests such that the extension team can own the tests.

Reviewed By: mdko

Differential Revision: D67214628

fbshipit-source-id: 2baf6c7cc99eaaac86ca4aab41011b5eedc1a501

hphp/test/run.php

@@ -562,6 +562,7 @@ function find_test_files(string $file): vec<string>{
     'cryptonative' => 'hphp/facebook/extensions/cryptonative/test',
     'thrift' => 'hphp/facebook/extensions/thrift/test',
     'flighttracker' => 'hphp/facebook/extensions/flighttracker/test',
+    'fci' => 'hphp/facebook/extensions/fci/test',
   ];
 
   $pattern = $mappage[$file] ?? null;