Default to RGBX on Windows when debugging assertions are enabled

[madsmtm]

To help expose issues with assuming the wrong pixel format.

Unsure yet if this is a good idea or not - it does match what I've done in #315 with making the byte stride debug_assertions-dependent, but it might also just end up causing more confusion than it helps.

Tested on:

• Windows

[MarijnS95]

On Android I force RGBX too during the resize, rather than RGBA:

softbuffer/src/backends/android.rs

Line 69 in afa87bb

Some(HardwareBufferFormat::R8G8B8X8_UNORM),

[madsmtm]

On Android I force RGBX too during the resize, rather than RGBA

This PR doesn't touch alpha-ness, it's more to help people catch problems with doing:

let buffer = surface.buffer_mut();
// Fill BGRA format because that's seems to be what's used everywhere.
buffer.data_u32().fill(u32::from_ne_bytes([b, g, r, a]));
buffer.present();

Which would be wrong, the user should fill based on PixelFormat::default(), but it would only be wrong on Android and Web, which are a bit more niche, and thus such a problem would likely only be caught late in development.