Pair missing from plutus.json definition

[SebastienGllmt]

What Git revision are you using?

aiken v1.0.29-alpha+16fb02e

What operating system are you using, and which version?

• [x] Linux / Ubuntu

Describe what the problem is?

Given the following Aiken code

pub type PairTest =
  Pair<Int, ByteArray>

pub type Action {
  PairTest { val: PairTest }
}

the following definition in plutus.json gets created

{
"my_project/validation/MintActions": {
  "title": "Action",
  "anyOf": [
    {
      "title": "PairTest",
      "dataType": "constructor",
      "index": 0,
      "fields": [
        {
          "title": "val",
          "$ref": "#/definitions/Pair$Int_ByteArray"
        }
      ]
    }
  ]
}

However, there is no definition entry for #/definitions/Pair$Int_ByteArray created

Note that this bug doesn't exist for List types or Tuple types. A proper List entry gets created. This issue seems to only affect Pair, and is probably because Pair is not mentioned in CIP57

What should be the expected behavior?

Either generate an entry for Pair, or change the schema to something else