JERSEY-2579: CDI transactional interceptor does not support passivation scope
 - any WAE should be retained within CDI runtime so that the interceptor
      does not need to keep HK2 locator reference
 - introduced WAE holder bean to keep any WAE in the actual request scope
 - also transaction exception mapper is now CDI managed

Change-Id: Ie903cae865f764d8c12d53e240654f09727eae21
Signed-off-by: Jakub Podlesak <jakub.podlesak@oracle.com>