add endpoint to get task types

[gabrieltaets-tw]

Context

• Added taskType and taskSubType parameters to management query endpoints.
• Added /getTaskTypes endpoint to retrieve list of registered task types and sub-types

these params and endpoints can be used by ninjas.transferwise.com/tasks to improve engineer experience with server-side filtering when supported

Checklist

• Change meets or does not compromise the Baseline Security Requirements

[Jarvvski]

lgtm, but needs AppEng approval

[wise-github-bot-app]

The approval(s) from Jarvvski do(es)n't fullfill the approvers requirements because:

• The approver's cost centre, ENGREG, maps to the ENGINEERING business function. As the code that was changed is owned by PLATFORM, this approval won't satisfy our separation of duties check. We'll need an additional approval from someone in PLATFORM. This approval may still help satisfy other codeowner requirements.