Update a contact on re-import rather than skipping it

#228 skipped a vCard whose UID the book already held. The reporter asked for
the opposite on #174 and he is right: the reason to import a file a second
time is usually that the first one was not right, so skipping means a
corrected export corrects nothing.

A merge, not a replacement. Properties the file carries overwrite what is
here; properties it does not mention are left alone, so a phone number added
in ihasmail after the first import survives a re-import of the original file.
The cost is that a field genuinely deleted at the source stays here, which is
the better way to be wrong -- the other way round loses work nobody asked to
lose. Worth confirming with him rather than assuming.

`addressBookIds` is left off the patch. The card is already in this book, so
saying it again says nothing, and saying it on a card that is also in another
book would move it.

Creates and updates now share one batch budget. Stalwart counts every object
in a /set together, so batching the halves separately would send 300 new and
300 changed as two calls of 300 and be refused for a limit of 500 that neither
half exceeds.

LDIF is untouched and still reports look-alikes without acting on them, since
what it should match on is the question still open on #223. Both imports keep
one answer shape so a caller need not know which it called; LDIF's `updated`
is always 0, which is the honest number rather than a missing field.

The message a vCard attached to a message shows changes with it: the newer
copy now wins instead of being dropped, so it says the contact was brought up
to date rather than that nothing was added.

Refs #223.

web/src/views/contacts/ContactsView.tsx

@@ -136,22 +136,24 @@ export function ContactsView({ id }: { id?: string }) {
        * LDIF may arrive as .ldif, .ldi, .txt or with no extension at all, and
        * the name is the least reliable thing about it.
        */
-      const { created, skipped, alike } = /^\s*BEGIN:VCARD/im.test(text)
+      const { created, updated, alike } = /^\s*BEGIN:VCARD/im.test(text)
         ? await contacts.importVCard(text, book.id)
         : await contacts.importLdif(text, book.id);
       /*
-       * The two counts kept apart, as the calendar import keeps them: "Imported
-       * 3 contacts" over a file of two hundred reads as a failure when the rest
-       * were simply already here, and a re-import of an unchanged export would
-       * otherwise report importing nothing at all.
+       * The counts kept apart, as the calendar import keeps them. "Imported 3
+       * contacts" over a file of two hundred reads as a failure when the other
+       * hundred and ninety-seven were updated, and a re-import of a corrected
+       * export -- the reason for doing this at all -- creates nothing and would
+       * otherwise report importing nothing.
        */
       const imported = plural(created, { one: "Imported {n} contact", other: "Imported {n} contacts" });
-      if (!created) toast.success(plural(skipped, { one: "Already here: {n} contact, nothing imported", other: "Already here: {n} contacts, nothing imported" }));
-      else if (skipped) toast.success(`${imported} · ${plural(skipped, { one: "{n} was already here", other: "{n} were already here" })}`);
+      const refreshed = plural(updated, { one: "{n} updated", other: "{n} updated" });
+      if (!created) toast.success(plural(updated, { one: "Updated {n} contact, nothing new", other: "Updated {n} contacts, nothing new" }));
+      else if (updated) toast.success(`${imported} · ${refreshed}`);
       else toast.success(imported);
       /*
        * Said separately, and after, because it is a different kind of fact.
-       * LDIF has no UID to match on, so nothing was skipped and nothing was
+       * LDIF has no UID to match on, so nothing was updated and nothing was
        * merged -- these are simply here twice now, and saying so is the whole
        * of what can honestly be said without guessing (#223).
        */