Adaptive spacebar

By default, pressing the spacebar in the viewport plays an animation or opens tools, depending on your settings.
In menus like Properties or Outliner, it doesn't do anything unless the mode is set to Search.
We can make spacebar action adapt to the window the cursor is in, when in viewport it would play animation or open tools, when in outliner it would open a search popup.

I would also add an option where the user can choose what to search - either all menus or the active window, like with Ctrl+F.