Move create/destroy actions for api/v1/statuses to namespace (#3678)

Each of mute, favourite, reblog has been updated to:

- Have a separate controller with just a create and destroy action
- Preserve historical route names to not break the API
- Mild refactoring to break up long methods

app/controllers/api/v1/statuses/reblogs_controller.rb

@@ -0,0 +1,35 @@
+# frozen_string_literal: true
+
+class Api::V1::Statuses::ReblogsController < Api::BaseController
+  include Authorization
+
+  before_action -> { doorkeeper_authorize! :write }
+  before_action :require_user!
+
+  respond_to :json
+
+  def create
+    @status = ReblogService.new.call(current_user.account, status_for_reblog)
+    render 'api/v1/statuses/show'
+  end
+
+  def destroy
+    @status = status_for_destroy.reblog
+    @reblogs_map = { @status.id => false }
+
+    authorize status_for_destroy, :unreblog?
+    RemovalWorker.perform_async(status_for_destroy.id)
+
+    render 'api/v1/statuses/show'
+  end
+
+  private
+
+  def status_for_reblog
+    Status.find params[:status_id]
+  end
+
+  def status_for_destroy
+    current_user.account.statuses.where(reblog_of_id: params[:status_id]).first!
+  end
+end