Add vertical mode and hide_text/hide_icons properties to TabBar

[StarryWorm]

• Prerequisite for Split inspector property sections into tabs #118359

This PR has two commits:

1. Adds a new vertical mode to TabBar. In this mode, the tabs are stacked on top of each other instead of next to one another
2. Adds two new toggles:
   2.1. hide_text: Hides the text on all tabs from displaying
   2.2. hide_icons: Hides the icons on all tabs from displaying

Below is a summary table (uses a mockup of the editor title bar)

--	Horizontal (default)	Vertical
show both (default)
hide text
hide icons

[kitbdev]

• Related Add vertical_mode toggle to TabBar godot-proposals#5031
• See Add support for vertical TabBar and side tab placement on TabContainer #116485

[StarryWorm]

I didn't see that PR, my bad, thanks kitbdev for linking