Support more superlatives/ordinals

[yhamoudi]

• Improve the support for single word superlatives: https://github.com/ProjetPP/PPP-QuestionParsing-Grammatical/blob/master/ppp_questionparsing_grammatical/data/superlative.py
• Support multiple words superlatives (ex: most beautiful) > More superlatives #94
• Support other kinds of extraction than first/last (23rd...)
  • Who was the 23rd president of the United States?
  • What is the second highest mountain peak in the world?
  • Who was the 16th President of the United States?

[yhamoudi]

by @Ezibenroc :

Who is the fourth president of the United States?
produces first(sort((United States,president,?),"default"))

The returned value is the same as:

Who is the first president of the United States?
produces first(sort((United States,president,?),"default"))

I don't know what is the expected returned value. I think we cannot describe it with the actual datamodel, since there is no operator for other ordinals than First and Last, and there is no operator for list difference.