Virtual Column Support

[clemens1483]

Hi,

we have been using this gem for a while without issue. However, I have recently tried to add a virtual column

add_column, :blah, :bluh, :date, as: "DATE(bleh)"

When I ran the migration, the entire entry for the blah table was deleted from the schema file and replaced with a commented error message

 # Could not dump table "blah" because of following NoMethodError
  #   undefined method `quoted_scope' for #<FixDBSchemaConflicts::SchemaDumper::ConnectionWithSorting:0x00007fd79d256aa8>

VERSION: 3.1
RAILS: 6.1
MYSQL: 5.7.22