fix(labels): Move the primary button out of breadcrumbs and into the project section

I know the issue didn't have the "Accepting merge requests", but it seemed like such a simple thing to fix (and it was) so I wanted to give it a go so that you can use it when/if the issue gets approved.

What does this MR do?

Currently, the primary button for creating a label is placed in the breadcrumb area, in contrast with the pattern followed by the rest of the pages like Issues.

The fix moves primary button from breadcrumb area for project and group labels.

Before	After

What are the relevant issue numbers?

#56558

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated via this MR
• Documentation reviewed by technical writer or follow-up review issue created
• Tests added for this feature/bug
• Tested in all supported browsers
• Conforms to the code review guidelines
• Conforms to the merge request performance guidelines
• Conforms to the style guides
• Conforms to the database guides
• Link to e2e tests MR added if this MR has Requires e2e tests label. See the Test Planning Process.
• Security reports checked/validated by reviewer