feat: various improvements

- Update to MidnightLib 1.7.0 and use its features to make the config screen more reliable
- Fix background gradient being opaque briefly when fading out while not in a world
- Fix 1.21.5 compat (still compatible with 1.21.4 as well :D)

common/src/main/java/eu/midnightdust/blur/mixin/MixinHandledScreen.java

@@ -24,6 +24,6 @@ public class MixinHandledScreen extends Screen {
     }
     @Inject(at = @At("HEAD"), method = "render")
     public void blur$processScreenChange(DrawContext context, int mouseX, int mouseY, float delta, CallbackInfo ci) {
-        if (PlatformFunctions.getPlatformName().equals("neoforge")) Blur.onRender(context, width, height, this.client);
+        if (PlatformFunctions.getPlatformName().equals("neoforge")) Blur.onRender(context, width, height, this.client, delta);
     }
 }