feat: add generate strong password button to Add Members form

Add a "Generate strong password" button with Sparkles icon to the
Add Members form in Settings > People. Generated passwords are shown
in plain text with a copy button and an amber warning to copy before
creating the user. Also upgraded the button style on the change
password page to match. Translated copy/warning strings for all 21
locales.

Closes #139

packages/shared/src/i18n/fr.ts

@@ -1516,6 +1516,10 @@ export const fr: TranslationKeys = {
       resetPasswordAction: "Reinitialiser le mot de passe",
       deleteUserAction: "Supprimer l'utilisateur",
       saveButton: "Enregistrer",
+      copyPasswordButton: "Copier le mot de passe",
+      passwordCopied: "Copie !",
+      copyPasswordWarning:
+        "Copiez ce mot de passe maintenant. Vous ne pourrez plus le voir apres la creation de l'utilisateur.",
     },
     teams: {
       heading: "Equipes",