Use quoted table name

[tagliala]

Retrieving quoted table name directly from the class instead of re-calculating it from the connection is an order of magnitude faster

class User < ActiveRecord::Base
  def self.qtn
    quoted_table_name
  end

  def self.cqtn
    connection.quote_table_name(table_name)
  end
end

Ruby 2.2 / Rails 5.0:

            User.qtn:  3003860.8 i/s
           User.cqtn:   259818.5 i/s - 11.56x  slower

Ruby 3.2 / Rails 7.0:

Comparison:
            User.qtn: 13504395.2 i/s
           User.cqtn:   517189.1 i/s - 26.11x  slower

[tagliala]

Looks like the timeline is one of the most expensive methods

Compared to the commit before optimizations started:

Before:

#timeline                        3.122635   0.367694   3.490329 (  8.078685)

After:

#timeline                        3.054792   0.358099   3.412891 (  7.965729)