Game object property fields type hints

It would be very helpful if I could provide hints on go.property which will be displayed in the property pane when hovered. Use case: I have, for example, a speed property, and I would like to have a description that explains that it is pixels per second. Or a timeout property, and I want to explain that it is in seconds.

Honestly, I feel like the property pane is lacking in the area of advance configurations, and I would like to have something like:

```lua
go.property("cooldown", {
default=2,
label="Cooldown (s)",
hint="The cooldown it takes between shots for the main character",
type="maybe have a selectable type? Like a dropdown and then have additional values?"
})
```

Start by tracing the go.property API to the property pane implementation. Determine how property metadata is represented and how hover text could be surfaced, then clarify the scope of the proposed type selector and additional values. Done should include a documented API for hints and the requested metadata appearing in the editor.

Written by the indexing model from the issue text.