chore: Wrap glyph shape variants with a Box

The GlyphShape enum contains three variants, all of them differ in size.
The None variant is used rarely, but the Swf variant isn't. By boxing
Swf and Drawing, we can reduce the amount of wasted memory.

Author: kjarosh

core/src/font.rs

@@ -220,7 +220,7 @@ impl FontFace {
                         );
                         Some(Glyph {
                             shape_handle: Default::default(),
-                            shape: GlyphShape::Drawing(drawing),
+                            shape: GlyphShape::Drawing(Box::new(drawing)),
                             advance,
                             character,
                         })
@@ -446,7 +446,9 @@ impl<'gc> Font<'gc> {
                 let glyph = Glyph {
                     shape_handle: None.into(),
                     advance: Twips::new(swf_glyph.advance.into()),
-                    shape: GlyphShape::Swf(RefCell::new(SwfGlyphOrShape::Glyph(swf_glyph))),
+                    shape: GlyphShape::Swf(RefCell::new(Box::new(SwfGlyphOrShape::Glyph(
+                        swf_glyph,
+                    )))),
                     character,
                 };
 
@@ -817,8 +819,8 @@ impl SwfGlyphOrShape {
 
 #[derive(Debug, Clone)]
 enum GlyphShape {
-    Swf(RefCell<SwfGlyphOrShape>),
-    Drawing(Drawing),
+    Swf(RefCell<Box<SwfGlyphOrShape>>),
+    Drawing(Box<Drawing>),
     None,
 }