Create custom cursor with directly with event loop

Replace the `CustomCursorBuilder` with the `CustomCursorSource` and
perform the loading of the cursor via the
`EventLoop::create_custom_cursor` instead of passing it to the builder
itself.

This follows the `EventLoop::create_window` API.

src/platform_impl/macos/cursor.rs

@@ -10,9 +10,8 @@ use once_cell::sync::Lazy;
 use std::ffi::c_uchar;
 use std::slice;
 
-use super::ActiveEventLoop;
 use crate::cursor::CursorImage;
-use crate::cursor::OnlyCursorImageBuilder;
+use crate::cursor::OnlyCursorImageSource;
 use crate::window::CursorIcon;
 
 #[derive(Clone, Debug, PartialEq, Eq, Hash)]
@@ -24,7 +23,7 @@ unsafe impl Send for CustomCursor {}
 unsafe impl Sync for CustomCursor {}
 
 impl CustomCursor {
-    pub(crate) fn build(cursor: OnlyCursorImageBuilder, _: &ActiveEventLoop) -> CustomCursor {
+    pub(crate) fn new(cursor: OnlyCursorImageSource) -> CustomCursor {
         Self(cursor_from_image(&cursor.0))
     }
 }

src/platform_impl/macos/event_loop.rs

@@ -35,6 +35,8 @@ use super::{
     monitor::{self, MonitorHandle},
     observer::setup_control_flow_observers,
 };
+use crate::platform_impl::platform::cursor::CustomCursor;
+use crate::window::{CustomCursor as RootCustomCursor, CustomCursorSource};
 use crate::{
     error::EventLoopError,
     event::Event,
@@ -77,6 +79,12 @@ pub struct ActiveEventLoop {
 }
 
 impl ActiveEventLoop {
+    pub fn create_custom_cursor(&self, source: CustomCursorSource) -> RootCustomCursor {
+        RootCustomCursor {
+            inner: CustomCursor::new(source.inner),
+        }
+    }
+
     #[inline]
     pub fn available_monitors(&self) -> VecDeque<MonitorHandle> {
         monitor::available_monitors()

src/platform_impl/macos/mod.rs

@@ -30,7 +30,7 @@ use crate::event::DeviceId as RootDeviceId;
 
 pub(crate) use self::cursor::CustomCursor as PlatformCustomCursor;
 pub(crate) use self::window::Window;
-pub(crate) use crate::cursor::OnlyCursorImageBuilder as PlatformCustomCursorBuilder;
+pub(crate) use crate::cursor::OnlyCursorImageSource as PlatformCustomCursorSource;
 pub(crate) use crate::icon::NoIcon as PlatformIcon;
 pub(crate) use crate::platform_impl::Fullscreen;