BDD: add create ContentTypeGroup feature file and sentences

Add create ContentTypeGroup feature file and sentences definitions interfaces
BDD: update single identifier sentences with ""
BDD: add get repository function
BDD: big refactor on BrowserContext to simplify maintenance
Merge pull request #125 from MLoureiro/bdd_browser_refactor

BDD big BrowserContext refactor
Merge pull request #108 from cleverti/bdd_create_contenttypegroup

Bdd create contenttypegroup