Various fixes and improvements (#12878)

* Fix unused role routes being generated

* Remove unused JavaScript code

* Refactor filters code to be DRYer

* Fix `.count == 0` comparisons to `.empty?` in views

* Fix filters in views

app/models/account_filter.rb

@@ -1,6 +1,21 @@
 # frozen_string_literal: true
 
 class AccountFilter
+  KEYS = %i(
+    local
+    remote
+    by_domain
+    active
+    pending
+    silenced
+    suspended
+    username
+    display_name
+    email
+    ip
+    staff
+  ).freeze
+
   attr_reader :params
 
   def initialize(params)

app/models/custom_emoji_filter.rb

@@ -1,6 +1,13 @@
 # frozen_string_literal: true
 
 class CustomEmojiFilter
+  KEYS = %i(
+    local
+    remote
+    by_domain
+    shortcode
+  ).freeze
+
   attr_reader :params
 
   def initialize(params)

app/models/instance_filter.rb

@@ -1,6 +1,11 @@
 # frozen_string_literal: true
 
 class InstanceFilter
+  KEYS = %i(
+    limited
+    by_domain
+  ).freeze
+
   attr_reader :params
 
   def initialize(params)

app/models/invite_filter.rb

@@ -1,6 +1,11 @@
 # frozen_string_literal: true
 
 class InviteFilter
+  KEYS = %i(
+    available
+    expired
+  ).freeze
+
   attr_reader :params
 
   def initialize(params)

app/models/relationship_filter.rb

@@ -0,0 +1,11 @@
+# frozen_string_literal: true
+
+class RelationshipFilter
+  KEYS = %i(
+    relationship
+    status
+    by_domain
+    activity
+    order
+  ).freeze
+end

app/models/report_filter.rb

@@ -1,6 +1,13 @@
 # frozen_string_literal: true
 
 class ReportFilter
+  KEYS = %i(
+    resolved
+    account_id
+    target_account_id
+    by_target_domain
+  ).freeze
+
   attr_reader :params
 
   def initialize(params)

app/models/tag_filter.rb

@@ -1,6 +1,16 @@
 # frozen_string_literal: true
 
 class TagFilter
+  KEYS = %i(
+    directory
+    reviewed
+    unreviewed
+    pending_review
+    popular
+    active
+    name
+  ).freeze
+
   attr_reader :params
 
   def initialize(params)