ProjectMembers#add should accept username if user_id is not provided

[talyssonoc]

Description

• Node.js version: 22.11.0
• Gitbeaker version: 41.3.0
• Gitbeaker release (cli, rest, core, requester-utils): REST
• OS & version: Manjaro with Linux kernel 6.12

The method ProjectMembers#add should be able to receive the username as an alternative to the user_id since the API allows it.

Steps to reproduce

• Instantiate Gitlab client from @gitbeaker/rest
• Try to call client.ProjectMembers.add('repo_id', 'username', AccessLevel.MAINTAINER)

Expected behaviour

It should not cause a type error and should call this API endpoint passing the username as the username field of the API endpoint payload

Actual behaviour

It causes a type error saying 'username' can't be a string, since the method assumes the second parameter is the user_id (source: https://github.com/jdalrymple/gitbeaker/blob/main/packages/core/src/resources/ProjectMembers.ts#L21), which is a number. Even if the type was right, the implementation still passes this attribute as the userId of the API (source: https://github.com/jdalrymple/gitbeaker/blob/main/packages/core/src/templates/ResourceMembers.ts#L67).

Possible fixes

I see three possibilities here:

• Make the second argument be of the type string | number. If it's a number assume it's the id, and if it's a string assume it's the username. This might be the safest backward-compatible option.
• Make the second argument an object of the type { username: string } | { userId: number } and send some of them conditionally when calling the API.
• Make the user_id and username fields part of the options argument instead of being an argument on itself.

Checklist

• I have checked that this is not a duplicate issue.
• I have read the documentation.

[jdalrymple]

🚀 Issue was released in 42.0.0 🚀