Add Mailing lists to Administration

A mailing list is an address that passes mail on to everyone on it. To
Stalwart it is its own object, x:MailingList, behind sysMailingList*, so
it gets its own section under Directory after Groups: search, fifty to a
page with each list's recipient count, and a panel to create, edit and
delete one.

Recipients are a property of the list, so unlike a group's members they
save with the rest of the panel. What Save sends for them is only what was
added and removed, one recipients/<address> pointer each -- the patch the
live server accepted -- so a recipient added elsewhere while the panel was
open is not taken out. They can be pasted several at a time, from a
spreadsheet column, a comma-separated line or Name <address>; anything with
an @ that is not an address stays in the box with a note. Past a dozen, a
filter narrows them.

That is all a list is in Stalwart -- no owners, moderation or posting
rules -- so that is all the panel offers.

The mock answers x:MailingList with two lists, the recipient set's live
shape, and the refusals a wrong address, a clash with an account and a
missing permission get.

Twenty-five new strings and one plural, in all nine catalogues.

web/src/views/admin/AdminView.tsx

@@ -5,6 +5,7 @@ import { AccountsAdmin } from "./AccountsAdmin";
 import { AdminDashboard } from "./AdminDashboard";
 import { DomainsAdmin } from "./DomainsAdmin";
 import { GroupsAdmin } from "./GroupsAdmin";
+import { ListsAdmin } from "./ListsAdmin";
 import { currentAdminSection } from "./AdminNav";
 import { usePermissions } from "./usePermissions";
 
@@ -12,6 +13,7 @@ const RENDER: Record<AdminSection, (id?: string) => ReactNode> = {
   dashboard: () => <AdminDashboard />,
   accounts: (id) => <AccountsAdmin selectedId={id} />,
   groups: (id) => <GroupsAdmin selectedId={id} />,
+  lists: (id) => <ListsAdmin selectedId={id} />,
   domains: (id) => <DomainsAdmin selectedId={id} />,
 };