Add popular avatar sizes for user, group and project

- Allow all supported avatar sizes

app/models/concerns/avatarable.rb

@@ -3,16 +3,11 @@
 module Avatarable
   extend ActiveSupport::Concern
 
-  ALLOWED_IMAGE_SCALER_WIDTHS = [
-    400,
-    200,
-    64,
-    48,
-    40,
-    26,
-    20,
-    16
-  ].freeze
+  USER_AVATAR_SIZES = [16, 20, 23, 24, 26, 32, 36, 38, 40, 48, 60, 64, 96, 120, 160].freeze
+  PROJECT_AVATAR_SIZES = [15, 40, 48, 64, 88].freeze
+  GROUP_AVATAR_SIZES = [15, 37, 38, 39, 40, 64, 96].freeze
+
+  ALLOWED_IMAGE_SCALER_WIDTHS = (USER_AVATAR_SIZES | PROJECT_AVATAR_SIZES | GROUP_AVATAR_SIZES).freeze
 
   included do
     prepend ShadowMethods