wso2api: use a cookie manager to reuse cookies among calls to lower glitches

## Problem being solved
Sometimes WSO2 API calls are out of sync because different nodes are being hit during mutations/checks. Using the same cookies would make the same server be reached amongst the sequential calls.

Note: Be aware that by doing this maybe we can hide a synchronisation issue on the underlying cluster too.

## Proposal
Use an cookie manager on the API calls to WSO2

