pass params to create method of all Collections.

We can pass params as an argument to create method, do not need call
parse_request in every create method.

create means the HTTP POST method, and POST requires body.
So every create needs params parsed from body.
But we do not need to parse params in every create.

Signed-off-by: ShaoHe Feng <shaohef@linux.vnet.ibm.com>