Repository: godot
Issue: Graphnode title and close icon horizontal position calculation missing theme constant when used for plugin
Labels: bug,topic:editor,topic:gui

### Godot version

3.4.4 stable

### System information

windows 10, gles3

### Issue description

when the default theme is applied to the graphnode used for a plugin, the title and close icon are positioned outward from where they should be. (editor theme in black is used for comparison, as it works correctly)

![image](https://user-images.githubusercontent.com/40372043/180027369-ef3c645f-cf22-4891-b8e9-c5460c42344a.png)

however, if this plugin scene is run standalone for testing the same theme applies their position correctly.

![image](https://user-images.githubusercontent.com/40372043/180016787-91bbe6f9-ba09-4935-8cfa-b21ace030177.png)


Having read through graphnode.cpp the position of both title and icon are meant to include the use of constants *_offset and *_h_offset from the current theme.

However, when importing default theme data using the 'theme import manager' the *_h_offset is not included.

simply adding the constant '*_h_offset' for both the 'title' and 'close' fixes the problem immediately for the default theme (when used as a plugin)

![image](https://user-images.githubusercontent.com/40372043/180027974-82a43411-3afe-4fb1-b38a-fe7e7865487c.png)

But it breaks the black editor theme position.
![image](https://user-images.githubusercontent.com/40372043/180028064-3f156a7a-0cdb-432f-872c-ae7a654c7718.png)

### Steps to reproduce

create a plugin with a single scene for the main screen which looks like:
![image](https://user-images.githubusercontent.com/40372043/180029558-f080be23-1c17-42c2-b43f-b10380a23e17.png)
(Circuits are the name for a type of GraphNode I'm creating)

** make sure that control and graphedit are set to full-rect and expand or they may not be visible on main screen when the plugin is enabled.

make sure to place the nodes side-by-side on the GraphEdit to see the changes happen clearly.

. add a new theme to the Main node
. edit the theme and select 'manage items'
. import only the 'selected frame' from the default theme 'GraphNode'
. import only the 'frame' stylebox, 'title' color, and 'close' icon from the editor theme 'GraphNode'
(technically the editor theme is applied automatically as the root theme, but if we want to see the effects when the we play the scene independently, then we need that data present)

this will allow us to see that nothing is changed about the default editor theme, other than when we override the constants when we add *_h_offset

Now play the scene as standalone, you should see this
![image](https://user-images.githubusercontent.com/40372043/180033796-73bd4b77-be20-4a22-8fa7-2c4a8afd0265.png)
they are the 'same' generally speaking, though it does appear as though the editor theme positions the title and icon more inward

go to settings > plugins and enable the plugin

![image](https://user-images.githubusercontent.com/40372043/180034202-23194730-fe1e-4eb4-b969-562b59293321.png)
notice that without any *_h_offset constants (by default when we create the theme) that the default theme places the title and icon incorrectly outward from where they should be.

. add title_h_offset and close_h_offset to the list of constants

notice that the default theme is now correct, but the editor theme places the title and icon too far inward. (it looks the same as when scene is played as before, but now the change seems off, as though it is too far inward)

it could just be a style choice, but looking at the way titles are for visual script nodes, it seems very much too far inward.
![image](https://user-images.githubusercontent.com/40372043/180034825-f5eb7c02-4016-48b2-9a3f-89ce469b91b4.png)

if we play the scene then we can see no difference from before

. delete the *_h_offset's, and notice the graphnodes do not retain the title and icon positioning (the calculations happen during every draw call)









### Minimal reproduction project

[def_theme_constants.zip](https://github.com/godotengine/godot/files/9152216/def_theme_constants.zip)