feature(backend-gitlab): add GraphQL support

[erezrokah]

Is your feature request related to a problem? Please describe.

Related to #5920.

Using the GitLab REST API can lead to performance issues and hitting rate limits.
Switching to GraphQL could help (we'll need to verify this).

Describe the solution you'd like
Similar to the GitHub backend, having use_graphql: true support for the GitLab backend

Describe alternatives you've considered
Keeping things as they are

Additional context
https://docs.gitlab.com/ee/api/graphql/

[imskr]

@erezrokah I want to work on this issue. Please assign :)

[erezrokah]

Thanks @imskr, my suggestion is to start from the method in this comment #5920 (comment)

[imskr]

Thanks @erezrokah so i have to create a new file GraphQLAPI.ts for this and add support for function #5920 (comment) right?

[erezrokah]

Hi @imskr, I would even say start with the function in the comment and edit the current file, to see if it works first.
Once we can see the performance improvement we can think about separating the REST/GraphQL logic.

[imskr]

Okay so I have to change https://github.com/netlify/netlify-cms/blob/0053ebbb46f189469c86518eb458daa34a8fec4d/packages/netlify-cms-backend-gitlab/src/implementation.ts#L199 to make use of entriesByFiles https://github.com/netlify/netlify-cms/blob/0053ebbb46f189469c86518eb458daa34a8fec4d/packages/netlify-cms-backend-gitlab/src/implementation.ts#L219 instead of allEntriesByFolder right? @erezrokah

[imskr]

@erezrokah can you give me a pointer on starting this?

[erezrokah]

Hi @imskr, sorry for the delay to respond. I've started looking into this myself (digging into the GraphQL API) to get some clarity on what needs to be done.

I can update here once I make some progress.

[imskr]

No worries @erezrokah let me know once you have something :)

[erezrokah]

Hello 👋 Posted and update in #5920 (comment)

[imskr]

Great @erezrokah I just checked it. I was looking for some good first issue if you can point me out that would be great 🙂 and also I can help on this on too though I'm new to the repo.

[erezrokah]

Hi @imskr, I think #6061 could be a good first issue that's entry level (this issue is more intermediate). I added a comment on that issue to get people started