Add a capsule group

src/Helper/StringHelper.php

src/Kernel.php

src/Repository/.gitignore

src/Repository/CapsuleRepository.php

src/Repository/GroupRepository.php

src/Repository/PendingEditorInvitationRepository.php

src/Repository/ResetPasswordRequestRepository.php

src/Repository/UserRepository.php

src/Retriever/ProjectRetriever.php

src/Security/AppCustomAuthenticator.php

src/Security/EmailVerifier.php

src/Security/UserChecker.php

templates/capsule/groups/edit.html.twig

templates/capsule/index.html.twig

translations/messages.en.yaml

translations/messages.fr.yaml

translations/validators.en.yaml

translations/validators.fr.yaml