[BUG][typescript-fetch] api model imports not using correct filename

[celluj34]

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator?
• 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?
• [Optional] Sponsorship to speed up the bug fix or feature request (example)

Description

Using the typescript-fetch generator, if you set additionalProperties.fileNaming = kebab-case, then any API tries to import the required models using the default PascalCase instead of the correct filename of kebab-case.

openapi-generator version

7.22. I am not sure if it's a regression as imports were using barrel imports before.

OpenAPI declaration file content or url

{
  "$schema": "https://raw.githubusercontent.com/OpenAPITools/openapi-generator-cli/master/apps/generator-cli/src/config.schema.json",
  "spaces": 2,
  "generator-cli": {
    "version": "7.22.0",
    "generators": {
      "myApi": {
        "inputSpec": "https://localhost:5001/openapi/v1.json",
        "output": "src/api-client/myApi",
        "generatorName": "typescript-fetch",
        "enablePostProcessFile": true,
        "additionalProperties": {
          "fileNaming": "kebab-case",
          "stringEnums": true,
          "supportsES6": true,
          "strictSpec": true
        },
        "globalProperty": {
          "supportingFiles": "",
          "models": "",
          "apis": "MyApi1"
        }
      }
    }
  }
}

Generation Details

Steps to reproduce

• using the above openapitools.json, run openapi-generator-cli generate.
• inspect any api.ts file, and see that it's using incorrect file import paths

Related issues/PRs

Suggest a fix

typescript-angular does not have this problem. they are using the operations array instead of the import array to import models.