Tweak Note.sort behaviour

The default mental model for notes is roughly analogous to the Bootstrap
alert levels [1]:

* Red: Error/Danger
* Yellow: Warning
* Green: Success
* Blue: Information

This commit tweaks the ordering such that notes are sorted as above. If
there's some sort of "Danger" note, then we want to show it before more
general "Information".

This ordering won't _always_ be correct, but it'll be Good Enough for
the majority of cases.

This also fixes the associated test. The `match_array` expectation is
order-agnostic [2]:

    expect([1, 2, 3]).to match_array([2, 3, 1]) # pass

[1] https://getbootstrap.com/2.2.0/components.html#alerts
[2] https://rspec.info/features/3-12/rspec-expectations/built-in-matchers/contain-exactly/

app/models/note.rb

@@ -24,10 +24,10 @@ class Note < ApplicationRecord
 
   cattr_accessor :default_style, default: 'original'
   cattr_accessor :style_labels, default: {
-    '🔵 Blue': 'blue',
     '🔴 Red': 'red',
-    '🟢 Green': 'green',
     '🟡 Yellow': 'yellow',
+    '🟢 Green': 'green',
+    '🔵 Blue': 'blue',
     'Original': 'original'
   }
 

spec/models/note_spec.rb

@@ -97,7 +97,7 @@ def plain_body
     end
 
     it 'sorts based on enum value index' do
-      is_expected.to match_array([original, blue_1, blue_2, red, green, yellow])
+      is_expected.to eq([red, yellow, green, blue_1, blue_2, original])
     end
   end