Improve rendering of Herald rules in "Another Herald rule..." field

Summary:
Fixes T9136.

• Fix a bug where the name is rendered improperly.
• Put disabled rules at the bottom.
• Always show the rule monogram so you can distingiush between rules with the same name.

Test Plan: {F6849915}

Maniphest Tasks: T9136

Differential Revision: https://secure.phabricator.com/D20798