Ajout d'un champ description aux périmètres et catégories de périmètres

src/UnicaenPrivilege/Entity/Db/AbstractPerimetre.php

...UnicaenPrivilege/Entity/Db/AbstractPerimetreCategorie.php

...y/Db/Mapping/UnicaenPrivilege.Entity.Db.Perimetre.dcm.xml

...ing/UnicaenPrivilege.Entity.Db.PerimetreCategorie.dcm.xml

...nicaenPrivilege/Entity/Db/PerimetreCategorieInterface.php

src/UnicaenPrivilege/Entity/Db/PerimetreInterface.php

src/UnicaenPrivilege/Form/Perimetre/CategorieForm.php

src/UnicaenPrivilege/Form/Perimetre/PerimetreForm.php

view/unicaen-privilege/perimetre-categorie/gerer.phtml

view/unicaen-privilege/perimetre-categorie/index.phtml