fix: bring bottom separator to back of content

[mxkae]

fixes #3061

[github-actions]

🤖 Pull request artifacts

file	commit
pr3190-stackable-3190-merge.zip	e4f45a3

[github-actions]

Try this Pull Request in the WordPress playground: https://playground.wordpress.net/?mode=seamless#{"landingPage":"/wp-admin/post-new.php?post_type=page","preferredVersions":{"php":"latest","wp":"latest"},"steps":[{"step":"login","username":"admin","password":"password"},{"step":"installPlugin","pluginZipFile":{"resource":"url","url":"https://github.com/raw/gambitph/Stackable/artifacts/pr3190-stackable-3190-merge.zip"}}]}

[andeng1106]

@mxkae Remaining issue:

• When I enable Bottom Separator for Feature and Feature Grid block, it looks glitchy on editor.
  • Issue on editor only
  • Issue started to happen on this pr build

Screen.Recording.2024-06-24.at.5.mp4

[bfintal]

Why did we pick z-index 5 here?

[mxkae]

Why did we pick z-index 5 here?

z-index 5 was used in this fix but z-index 3 also works for me. Updated it for now to use z-index 3.