Revert #87462 "Fix PopupMenu doesn't respect its ScrollContainer's margins"

[radiantgurl]

• reverts Fix PopupMenu doesn't respect its ScrollContainer's margins #87462
• closes Right clicking in the editor to open properties of a certain element instantly selects what's under cursor. #93265
• reopens PopupMenu doesn't respect the content margins of it's ScrollContainer's StyleBox #87461

[radiantgurl]

The ideal solution to be is not to revert the PR that attempts to fix a bug and introduces another one, but to have both of them fixed instead.

[radiantgurl]

I swear to god Windows.....
It failed to download the D3D12 SDK with an HTTP error 503..

[akien-mga]

So, I've been waiting to see if more investigation could be done on #93265 to understand the nature of the issue.

Reverting this visual change seems to only be addressing a symptom of the bug by changing slightly a position so that the bug isn't triggered. I'm not too keen on making such a change without understanding the root cause of the issue, as it means that issue may happen in other areas of the editor, or in user projects.

So far neither @bruvzg nor I managed to reproduce the issue on Linux, so it seems to affect only a subset of users. We'd need to identify which.

So I'd prefer not to merge this and instead go back to further debugging on #93265. It's probably too late to find a fix for 4.3-stable, but this is something we should hopefully be able to solve quickly after and backport to 4.3.1.