fix(AppAPIService): encode query parameter arrays via http_build_query

[edward-ly]

Resolves #384. If the checks still pass and this gets merged, perhaps we should take a look at other apps to see if they need to be updated in the same way.

[andrey18106]

LGTM, better also to double check within the issue to confirm it works as expected now.

[bigcat88]

let's merge this and request backports.

I'll test it heavily this week with Flow and Visionatrix, after that we can approve & merge backports.