Add option to start window maximized

## What problem does this solve or what need does it fill?

There is currently no functionality to start bevy with a maximized window. Ideally a window should remember its state between relaunches, including whether its maximized.

## What solution would you like?

While you can technically use `window.set_maximized(true)` before Bevy launches, this creates a window which maximized on the next tick which looks janky. Instead it should just create the window maximized.

Start by tracing Bevy's window-creation path and the existing `window.set_maximized(true)` behavior described in the issue. Done means the window is created maximized at launch without a one-tick visual change; determine whether remembering the maximized state between relaunches is included in the final scope.

Written by the indexing model from the issue text.