scala-cask fix: Added support for 'additionalProperties:true'

[aaronp]

additionalProperties means the request can contain arbitrary additional properties, and so this change adds an 'additionalProperties' field to request objects which is a json type.

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[aaronp]

Hello @Bouillie / @chameleon82 / @clasnake

Apologies for the spam - I'm just following the "tag tech committee members" instruction for this PR to the scala-cask generator

Many many thanks in advance!

[aaronp]

Thanks @wing328 so much as ever for your time and great comments! I've made an update to coincide w/ the conversation, so hopefully that makes sense

[wing328]

thanks for the PR

let's give it a try