Feature request: Additional UI Elements for Desktop target: Windows, Tooltips, Radio Button, Editable Text, Wrapping Text Areas

Korge is missing a number of UI elements which, while of less relevance to mobile targets, would still be of great use to desktop and even web games.

- [x] Window - a draggable, skinable container with a title.
- [ ] Modal dialog - a specialization of Window, which blocks all other UI interactions
- [ ] Tooltips - a container which is drawn on top of all other elements, triggered by hovering over a view. Should be flexible enough to support any nested content
- [x] Editable Text - pretty much essential, even for mobile targets - how else can I enter my name for a hgh score? 😄
- [x] Radio Button control - perhaps additional logic on the existing uiCheckBox element
- [ ] Wrapping Text Area - for longer paragraphs of text

Stretch goals for additional UI elements:

- [ ] Table layouts for tabular data
- [ ] BBCode for formatting text

I have been experimenting with draft implementations of some of these here https://github.com/v79/KorgeExperiments - none of these are remotely production ready.

**My number one priority is Tooltips**, as I can't find a way of ensuring they are drawn on top of all other elements. I don't think Korge provides a layering system or a Z-axis for 2D elements.

**Use cases**: Strategy and simulation games, 4X games, RPGs - For example, the earlier Sim City games, Civilization, grand strategy games all make extensive use of windowing and dialogs, and tooltops. RPGs would really need paragraphs of text without hard-coding newline characters.

Start by reviewing the draft implementations in KorgeExperiments and the existing Korge UI elements, focusing first on the requested tooltip behavior. Define the initial scope and identify how completion will be verified for tooltips, modal dialogs, or wrapping text areas before attempting a production-ready implementation.

Written by the indexing model from the issue text.