[Scala] Overriden objectmapper wasn't used in deserialisation

[lachatak]

Description

Overriden objectmapper is not used in deserialisation because in the api.mustache there is a typo so there is a new ApiInvoker creation every time you deserialise a response via the companion object. The side effect is that you cannot override the object mapper in the invoker.

api.mustache
{{#returnType}} Some(ApiInvoker.deserialize(s, "{{returnContainer}}", classOf[{{returnBaseType}}]).asInstanceOf[{{returnType}}])

Steps to reproduce

Generate any Scala client from any swagger document. See samples..

Suggest a Fix

Change api.mustache to be the following
{{#returnType}} Some(apiInvoker.deserialize(s, "{{returnContainer}}", classOf[{{returnBaseType}}]).asInstanceOf[{{returnType}}])

I have a fix ready to PR.

[wing328]

@lachatak thanks for reporting the issue. Please kindly submit a PR so that we can review the change.

[lachatak]

PR was created:
#4533
I hope it is fine.

[wing328]

Closed via #4534