Check component props for untranslated literals, and fail on a finding

i18n-literals checked title, aria-label, placeholder and alt on elements,
but not the same English passed to a component, so a MenuItem label or a
Popover ariaLabel written as a literal went through. It also excused a
literal that happened to be a catalogue key. That exemption is meant for
English held in a constant and translated where it renders, and a literal
written straight into a JSX attribute has no such render site. No
component passes its props through t(). And neither half of i18n:check
was run with --check, so a finding printed and the script still exited 0.

Component props are checked now, a key no longer excuses a literal in an
attribute, and both scripts run with --check. That found 28 strings
rendering English in every language: 19 already had keys and are wrapped,
and 9 are new keys in all nine catalogues. The contact editor's Save and
Saving… buttons are wrapped as well, on the same line.

web/src/views/mail/MailboxTree.tsx

@@ -471,7 +471,7 @@ function MailboxMenu({ mailbox: m, onClose, onCreateChild, onShare }: { mailbox:
       )}
       <MenuItem icon={<FolderPlus size={16} />} label={t("New subfolder")} onClick={onCreateChild} disabled={!m.myRights.mayCreateChild} />
       <MenuItem icon={<Pencil size={16} />} label={t("Rename")} onClick={() => void rename()} disabled={isSpecial || !m.myRights.mayRename} />
-      <MenuItem icon={m.isSubscribed ? <EyeOff size={16} /> : <Eye size={16} />} label={m.isSubscribed ? "Hide from list" : "Show in list"} onClick={() => void useMail.getState().updateMailbox(m.id, { isSubscribed: !m.isSubscribed })} disabled={m.role === "inbox"} />
+      <MenuItem icon={m.isSubscribed ? <EyeOff size={16} /> : <Eye size={16} />} label={m.isSubscribed ? t("Hide from list") : t("Show in list")} onClick={() => void useMail.getState().updateMailbox(m.id, { isSubscribed: !m.isSubscribed })} disabled={m.role === "inbox"} />
       {/* Sharing a mail folder is withdrawn, not removed: Stalwart accepts and
           stores the share, and it never reaches the other account -- its own
           docs list calendars, address books and files as shareable and not mail