[BUG][TYPESCRIPT-FETCH] Incorrect generated import for Metadata x MetaData (different case)

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

When API definition has two models which differ in upper/lower case - i.e. Metadata & MetaData, the generated code cannot be compiled due to different imported and generated file.

openapi-generator version

Both 7.17.0 and the latest master 7.18.0-SNAPSHOT.

Not sure if it's a regression, I use this tool in my current project newly.

OpenAPI declaration file content or url

https://gist.github.com/simeonborko/3024ac82ffee30702533a2c571edc964

Generation Details

docker run --user 1000:1000 --rm -v $PWD:/local openapitools/openapi-generator-cli:latest generate -i /local/api.json -g typescript-fetch -o /local/reproduction

Steps to reproduce

# run the command above

cd reproduction/models
ls
# index.ts  Metadata0.ts  MetaData.ts

cat index.ts

/* tslint:disable */
/* eslint-disable */
export * from './MetaData';
export * from './Metadata';

Related issues/PRs

Suggest a fix

Start with the supplied OpenAPI declaration and reproduce using the documented Docker command with the typescript-fetch generator. Compare the generated models/Metadata0.ts, MetaData.ts, and models/index.ts; done means the generated TypeScript imports correspond to files that compile for models differing only by case.