API: Use `visibility` as string parameter everywhere (!9337) · Merge Requests · GitLab.org / GitLab FOSS

API: Use `visibility` as string parameter everywhere

What does this MR do?

Instead of exposing the visibility_level as an Integer, expose it as visibility String.

Are there points in the code the reviewer needs to double check?

Why was this MR needed?

Screenshots (if relevant)

Does this MR meet the acceptance criteria?

Changelog entry added
Documentation created/updated
API support added
Tests
- Added for this feature/bug
- All builds are passing
Conform by the merge request performance guides
Conform by the style guides
Branch has no merge conflicts with master (if it does - rebase it please)
Squashed related commits together

What are the relevant issue numbers?

Closes #27501 (closed)

## What does this MR do?

Instead of exposing the `visibility_level` as an Integer, expose it as `visibility` String.

## Are there points in the code the reviewer needs to double check?

## Why was this MR needed?

## Screenshots (if relevant)

## Does this MR meet the acceptance criteria?

- [x] [Changelog entry](https://docs.gitlab.com/ce/development/changelog.html) added
- [x] [Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)
- [x] API support added
- Tests
  - [x] Added for this feature/bug
  - [ ] All builds are passing
- [x] Conform by the [merge request performance guides](http://docs.gitlab.com/ce/development/merge_request_performance_guidelines.html)
- [x] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [x] Branch has no merge conflicts with `master` (if it does - rebase it please)
- [ ] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

## What are the relevant issue numbers?

Closes #27501