Disable antialiasing on the DynamicFont outline as well when requested

This partially addresses
https://github.com/godotengine/godot-proposals/issues/943.

(cherry picked from commit 2919fc73174a3c751405ce46ceed3ef71ea62966)

doc/classes/DynamicFontData.xml

@@ -12,7 +12,7 @@
 	</methods>
 	<members>
 		<member name="antialiased" type="bool" setter="set_antialiased" getter="is_antialiased" default="true">
-			If [code]true[/code], the font is rendered with anti-aliasing.
+			If [code]true[/code], the font is rendered with anti-aliasing. This property applies both to the main font and its outline (if it has one).
 		</member>
 		<member name="font_path" type="String" setter="set_font_path" getter="get_font_path" default="&quot;&quot;">
 			The path to the vector font file.

scene/resources/dynamic_font.cpp

@@ -577,7 +577,7 @@ DynamicFontAtSize::Character DynamicFontAtSize::_make_outline_char(CharType p_ch
 		goto cleanup_stroker;
 	if (FT_Glyph_Stroke(&glyph, stroker, 1) != 0)
 		goto cleanup_glyph;
-	if (FT_Glyph_To_Bitmap(&glyph, FT_RENDER_MODE_NORMAL, 0, 1) != 0)
+	if (FT_Glyph_To_Bitmap(&glyph, font->antialiased ? FT_RENDER_MODE_NORMAL : FT_RENDER_MODE_MONO, nullptr, 1) != 0)
 		goto cleanup_glyph;
 
 	glyph_bitmap = (FT_BitmapGlyph)glyph;