[Task] Implement text operator

What should be done

• Add $text in grammar: (Check https://github.com/mongodb-js/mongodb-language-model/blob/master/grammar.pegjs for more info)

  • Add text_operator = "$text"
  • Uncomment text_clause line 42
  • Implement text_clause https://github.com/mongodb-js/mongodb-language-model/blob/master/grammar.pegjs#L23
  • We need to add text opêrator search/caseSensitive/diacriticSensitive

• In exec.ex implement a function that match pos "text-clause"

  • for search operator:
    • split on each space check if any? match elem
    • if the search string contains \, do a split on "\"" and match the word/prhases on index 1 of split result
  • if case sensitive at false (true by default) do a String.downcase
  • for diacriticSensitive
    • true match string without traitement
    • false remove accent, you can used |> String.normalize(:nfd) |> String.replace(~r/[^A-z\s]/u, "") |> String.replace(~r/\s/, "-")

Start by comparing the text_operator and text_clause definitions in grammar.pegjs, then inspect exec.ex for the matching point named "text-clause". Implement search handling with quoted phrases, case sensitivity, and diacritic sensitivity, and consider the task complete when all listed text-operator behaviors are supported.