Use SDL_bool where appropriate in SDL events

This involved changing button state from Uint8 to SDL_bool, and made SDL_PRESSED and SDL_RELEASED unnecessary.

Fixes https://github.com/libsdl-org/SDL/issues/10069

test/testmanymouse.c

@@ -285,7 +285,7 @@ static void HandleMouseButton(SDL_MouseButtonEvent *event)
             continue;
         }
         if (event->which == mouse_state->instance_id) {
-            if (event->state) {
+            if (event->down) {
                 mouse_state->button_state |= SDL_BUTTON(event->button);
             } else {
                 mouse_state->button_state &= ~SDL_BUTTON(event->button);