Docs: image realignment

What does this MR do?

Many images have diverged between the CE and EE docs. The vast majority diverged when they were compressed to save space, and the compression algorithm gave slightly different file sizes. They are visually identical, but the file size difference causes them to appear different in a diff.

Two images were newer in CE, and are ported to EE in https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/10510.

Three images diverged because the newer versions in EE were not ported to CE, so the newer versions are ported here as well:

• doc/user/project/img/labels_default.png
• doc/user/project/img/labels_list.png
• doc/user/group/img/create_new_group_info.png

Related issues

Related to &199 (closed)

Author's checklist

• Follow the Documentation Guidelines and Style Guide.
• Link docs to and from the higher-level index page, plus other related docs where helpful.
• Apply the ~Documentation label.

Review checklist

All reviewers can help ensure accuracy, clarity, completeness, and adherence to the Documentation Guidelines and Style Guide.

1. Primary Reviewer

• Review by a code reviewer or other selected colleague to confirm accuracy, clarity, and completeness. This can be skipped for minor fixes without substantive content changes.

2. Technical Writer

• Optional: Technical writer review. If not requested for this MR, must be scheduled post-merge. To request for this MR, assign the writer listed for the applicable DevOps stage.

3. Maintainer

1. Review by assigned maintainer, who can always request/require the above reviews. Maintainer's review can occur before or after a technical writer review.
2. Ensure a release milestone is set and that you merge the equivalent EE MR before the CE MR if both exist.
3. If there has not been a technical writer review, create an issue for one using the Doc Review template.