Add invite user feature for admin

internal/i18nresource/locale.en.toml

@@ -1,4 +1,5 @@
 InvalidCredentials = "Invalid credentials."
+UserNotActivated = "User is not activated."
 AuthenticationSuccess = "Authentication was a success."
 ValidationRequired = "This field is required."
 ValidationTooShort = "This field is too short. It should be at least %s characters."

internal/i18nresource/locale.fr.toml

@@ -1,4 +1,5 @@
 InvalidCredentials = "Identifiants invalides."
+UserNotActivated = "L'utilisateur n'est pas activé."
 AuthenticationSuccess = "Connexion réussie."
 ValidationRequired = "Ce champ est requis."
 ValidationTooShort = "Ce champ est trop court. Il devrait contenir au moins %s caractères."