[BUG][Kotlin] OK HTTP: collectionDelimiter not imported

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator (example)?
• Have you tested with the latest master to confirm the issue still exists?
• Have you searched for related issues/PRs?
• What's the actual output vs expected output?
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Description

If a generated Api Client has a header field with schema array of an enum it uses the method collectionDelimiter which is provided in the infrastructure package (ApiAbstractions.kt)

openapi-generator version

7.10.0

OpenAPI declaration file content or url

Just need an enum array as parameter anywhere.
`
parameters:

• name: values
  in: header
  required: false
  schema:
  type: array
  description: All goods receipt types that should be sent back to the device
  items:
  type: string
  description: Type of goods receipt request
  enum:
  - MULTIPLE
  - ENUM
  - VALUES
  `

Generation Details

Configure the kotlin generator to use okhttp

Steps to reproduce

Generate any API

Suggest a fix

Add the collectionDelimiter import always, or atleast when using it.
File https://github.com/OpenAPITools/openapi-generator/blob/master/modules/openapi-generator/src/main/resources/kotlin-client/libraries/jvm-okhttp/api.mustache

Start with modules/openapi-generator/src/main/resources/kotlin-client/libraries/jvm-okhttp/api.mustache and inspect how collectionDelimiter is referenced, along with ApiAbstractions.kt where it is provided. Generate a Kotlin client using the JVM OkHttp library with an enum array header parameter. Done means the generated client imports collectionDelimiter when needed and compiles successfully.