rgw: add request time into beast log instead of current time

rgw: add request time into beast log instead of current time

Change time format on the line that prints a
summary of the request in apache common log format
to match the format suggested by apache and encapsulate
apache time formatting in stream output operator.

For more information visit:
https://httpd.apache.org/docs/current/logs.html#common

Signed-off-by: Ali Maredia <amaredia@redhat.com>
Co-authored-by: Casey Bodley <cbodley@redhat.com>