API to create gitlab ci yml merge request

What does this MR do and why?

We want to create a button that creates a merge request including ci config file if a project is missing one.

How to set up and validate locally

1. Use the below curl to create a merge request for a project

curl --location --request POST 'http://{GDK_HOST}//api/v4/projects/:id/create_ci_config' \
--header 'Authorization: YOUR_TOKEN' 

2. It should create a merge request including a ci config file.
3. It should name the file gitlab-ci.yml if the custom ci config name is not configured in Project -> Settings -> CI/CD
4. After merging use the same API to check if it throws an error.

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.

Related to #378855 (closed)