Tidy up popup layouts

- Settings: labels in one column and switches and number buttons lined
  up in another, with margins inside the panel
- Log: title and margins; text no longer touches the panel edge
- Sync result: error list centred under its header, which now reads
  Errors instead of CatchedErrors
- About: text wraps inside the panel instead of running under the
  scrollbar
- Character select: wider panel, so the right column of characters is
  no longer right next to the scrollbar

AboutWindow.tscn

@@ -30,10 +30,11 @@ vertical_alignment = 1
 
 [node name="ScrollContainer" type="ScrollContainer" parent="AboutPanel" unique_id=417677913]
 layout_mode = 0
-offset_left = 10.0
+offset_left = 20.0
 offset_top = 50.0
-offset_right = 590.0
+offset_right = 580.0
 offset_bottom = 630.0
+horizontal_scroll_mode = 0
 
 [node name="ContentVBox" type="VBoxContainer" parent="AboutPanel/ScrollContainer" unique_id=1746337912]
 layout_mode = 2
@@ -47,7 +48,6 @@ size_flags_horizontal = 3
 horizontal_alignment = 1
 
 [node name="DescriptionLabel" type="Label" parent="AboutPanel/ScrollContainer/ContentVBox" unique_id=543094263]
-custom_minimum_size = Vector2(560, 0)
 layout_mode = 2
 size_flags_horizontal = 3
 text = "Try your video game music knowledge with this VGM randomizer, invite your friends and see who is the best."
@@ -56,7 +56,6 @@ autowrap_mode = 2
 
 [node name="WhatsNewLabel" type="Label" parent="AboutPanel/ScrollContainer/ContentVBox" unique_id=1363040291]
 unique_name_in_owner = true
-custom_minimum_size = Vector2(560, 0)
 layout_mode = 2
 size_flags_horizontal = 3
 autowrap_mode = 2