Remove the GLQL popover and experimental badge (for glql_work_items)

What does this MR do and why?

• Remove the GLQL popover: The GLQL popover was introduced in 18.3 as a promotional message in the rich text editor. Three milestones later, it is now time to remove it. We also remove the New badge on the Embedded views option in RTE and PTE more dropdown.
• Remove experimental badge on embedded views when glql_work_items FF is enabled. Since the FF is now enabled for everyone by default.
• Add some padding on top for empty state in embedded views.

References

• https://gitlab.slack.com/archives/CETG54GQ0/p1759335292812199

  

• https://gitlab.slack.com/archives/CETG54GQ0/p1765280057944989

  

Screenshots or screen recordings

Before	After
	The popup is gone

How to set up and validate locally

1. Login into GitLab, delete all local storage.
2. Click the + dropdown in rich text editor. The embedded views popover should not appear. The "New" badge next to embedded views menu item should also not appear.
3. Create an embedded view by selecting the dropdown item.
4. Save the comment.
5. The "Experiment" badge should disappear.
6. If the result has no data, the top padding should be good.

MR acceptance checklist

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