Fix signal tooltip not leaving

[kitbdev]

• fixes Signal tooltip doesn't go away when moving mouse to another signal in single window mode #93698
• fixes Connecting a signal with a double click is too difficult #92382

Changes it to use the regular tooltip system.
It wasn't working since the tree doesn't emit mouse_exit signals whenever different items are hovered, and the EditorHelpBitTooltip system expected that.

This also affects the behavior when not in single window mode, it should be better.

[kitbdev]

The issue this fixes isn't specific to linux.

The behavior was also messed up when not in single window mode as well, it wasn't changing when hovering over another item. This is also fixed by this PR.

• Also found Connecting a signal with a double click is too difficult #92382

[dalexeev]

This makes it impossible to hover over the tooltip, so I would prefer to fix this another way. Also, I'm not sure that you are fixing the real cause of the bug, and not its symptom.

The fact that Tree elements are not individual controls (unlike the Inspector) of course makes using the tooltip less convenient: you need to first leave the Signals dock and hover over another signal again, rather than simply moving the cursor to another signal. But I think that it's a minor usability issue, not the cause of the bug with tooltip duplication in some cases.

[kitbdev]

In single window mode, hovering over the tooltip has no use at all (doesn't get input), so I feel like this feature needs some more time in this case (see #92545).
I did it this way because it was quicker for 4.3, a full solution to it can be worked out later.

I could have fixed it by storing a reference to the EditorHelpBitTooltip in the connections dock to prevent duplicates, but that feels like a workaround since this system is trying to subvert the existing tooltip system, and it wouldn't fix the other issues with it.

Also I think that being able to get tooltips for different signals easily is more important than being able to click on links in the descriptions, since many signals don't have links and their full documentation can be opened to be able to follow the links anyway.

[Mickeon]

I'm in favour of fixing this annoyance first, and then coming up with a way for the tooltip to be clickable later. #89058 did way too much at once, more than it was supposed to by its title.

[dalexeev]

I'll take a look at this soon to see if I can come up with a better solution.

I could have fixed it by storing a reference to the EditorHelpBitTooltip in the connections dock to prevent duplicates, but that feels like a workaround since this system is trying to subvert the existing tooltip system, and it wouldn't fix the other issues with it.

We could add a static variable to EditorHelpBitTooltip to keep track of the last tooltip displayed. And when opening a new one, automatically hide the previous one if for some reason it is still there. But this doesn't actually fix the real bug that exists in single window mode.

Also I think that being able to get tooltips for different signals easily is more important than being able to click on links in the descriptions, since many signals don't have links and their full documentation can be opened to be able to follow the links anyway.

Not only clickable links, but also the ability to scroll content.

[dalexeev]

• See Editor: Fix EditorHelpBitTooltip for Signals dock #93967.

[KoBeWi]

Personally I prefer the other PR, but either one is fine for now. The tooltips need fixing anyway.

[akien-mga]

Superseded by #93967 (for now).