Add ability to filter individual posts (#18945)

* Add database table for status-specific filters

* Add REST endpoints, entities and attributes

* Show status filters in /filters interface

* Perform server-side filtering for individual posts filters

* Fix filtering on context mismatch

* Refactor `toServerSideType` by moving it to its own module

* Move loupe and delete icons to their own module

* Add ability to filter individual posts from WebUI

* Replace keyword list by warnings (expired, context mismatch)

* Refactor server-side filtering code

* Add tests

app/controllers/filters/statuses_controller.rb

@@ -0,0 +1,49 @@
+# frozen_string_literal: true
+
+class Filters::StatusesController < ApplicationController
+  layout 'admin'
+
+  before_action :authenticate_user!
+  before_action :set_filter
+  before_action :set_status_filters
+  before_action :set_body_classes
+
+  PER_PAGE = 20
+
+  def index
+    @status_filter_batch_action = Form::StatusFilterBatchAction.new
+  end
+
+  def batch
+    @status_filter_batch_action = Form::StatusFilterBatchAction.new(status_filter_batch_action_params.merge(current_account: current_account, filter_id: params[:filter_id], type: action_from_button))
+    @status_filter_batch_action.save!
+  rescue ActionController::ParameterMissing
+    flash[:alert] = I18n.t('admin.statuses.no_status_selected')
+  ensure
+    redirect_to edit_filter_path(@filter)
+  end
+
+  private
+
+  def set_filter
+    @filter = current_account.custom_filters.find(params[:filter_id])
+  end
+
+  def set_status_filters
+    @status_filters = @filter.statuses.preload(:status).page(params[:page]).per(PER_PAGE)
+  end
+
+  def status_filter_batch_action_params
+    params.require(:form_status_filter_batch_action).permit(status_filter_ids: [])
+  end
+
+  def action_from_button
+    if params[:remove]
+      'remove'
+    end
+  end
+
+  def set_body_classes
+    @body_classes = 'admin'
+  end
+end