Rename and migrate art_museum.png to museum_art.png in node_types table
user
```ruby
class ChangeArtMuseumToMuseumArt < ActiveRecord::Migration
  class LocalNodeType < ActiveRecord::Base
    self.table_name = 'node_types'
    validates :icon, presence: true
  end

  # Rename art_museum.png to museum_art.png but keep same identifier & osm_value
  def up
    node_type = LocalNodeType.find_by(id: 153)
    if node_type.nil?
      return
    else
      node_type.icon = 'museum_art.png'
      node_type.save
    end
  end

  def down
    node_type = LocalNodeType.find_by(id: 153)
    if node_type.nil?
      return
    else
      node_type.icon = 'art_museum.png'
      node_type.save
    end
  end
end
```
assistant