Allow dots in group names to pass validation for Create Group and Edit Group forms

What does this MR do?

Allows dots within group names to pass form validation when creating or editing a group.

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

Nope, pretty straight forward.

Why was this MR needed?

Although group names with dots are allowed, our frontend validation mistakenly invalidates them

Screenshots (if relevant)

Before:

After:

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?

Related to: #24622 (closed) Closes #24903 (closed)