Rename OptionButton to DropDownList

[madmiraal]

As originally mentioned in #6558, the OptionButton is actually a Drop-Down List.

This PR renames OptionButton to DropDownList.

Closes godotengine/godot-proposals#1998

[aaronfranke]

Can we just call it DropDown (or similar)? I don't think the "List" suffix is ideal for a node type.

[groud]

Can we just call it DropDown (or similar)? I don't think the "List" suffix is ideal for a node type.

I was thinking maybe we should go for DropDownButton, since it inherits from Button.

[madmiraal]

I don't think the "List" suffix is ideal for a node type.

We already have ItemList

I was thinking maybe we should go for DropDownButton, since it inherits from Button.

It's only a Button, because, within the engine, it inherits Button, but it's a Drop-Down List. Note: Checkbox also inherits Button, but it's not called CheckboxButton. I think it should be called what it is.

[MaaaxiKing]

A bit long, but DropDownListButton would be the most correct and detailed one.

[aaronfranke]

It's only a Button, because, within the engine, it inherits Button, but it's a Drop-Down List.

Isn't it a button that creates a drop-down list when clicked?

[MaaaxiKing]

Strictly speaking, yes.

[reduz]

Is not the most common name for this to be ComboBox ? We have CheckBox already.

[madmiraal]

A Combobox is something different. A Combobox is a DropDownList with a single line, editable text box that we call a LineEdit that allows the user to either select one of the DropDownList items or enter their own value.

[YuriSizov]

The proposal was approved, but we picked a different option. This PR is pretty old, so it's better it is remade from scratch for the new name.