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

Locate the TypeScript code that makes the WSO2 API calls and trace the sequential mutation and check operations described in the issue. Determine where their request state is created, then verify that the completed calls reuse one cookie context without changing unrelated behavior; the issue provides no named test or file.

Written by the indexing model from the issue text.