radosgw-admin: fixes for period push/pull

radosgw-admin: fixes for period push/pull

for send_to_remote_gateway() to work, the push and pull commands had to
be moved to the not-raw-storage section, because RGWRados::init_complete
is needed to set up the gateway connections

the period push command was changed to send the json-encoded period
data, so an in_data argument was added to send_to_remote_gateway()

the parameters for push and pull needed to remain separate from the
request_uri, because request_uri is used as input for the auth digest,
and the server side parses the parameters separately as well

Implements feature #11944

Signed-off-by: Casey Bodley <cbodley@redhat.com>