Add filtering support to the /v1/acl/* APIs

CONSUL_VERSION : 1.9.0

I try to filter the result return by the endpoint /acl/tokens like the following :

Curl request :
`curl -H "X-Consul-Token: MYTOKEN" -X GET http://localhost:8500/v1/acl/tokens --data-urlencode 'filter=Description=="crep"'`

Api call :
`acls, _, err := acl.TokenList(&api.QueryOptions{Filter: "Description == crep"})`

The result are not filtered.
I have followed the documentation (https://www.consul.io/api-docs/features/filtering) without success.
Can you tell me if my filter is wrong or if you are able to reproduce my problem ?

Thanks for your help