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/store/__tests__/ldif-likeness.test.ts

@@ -72,7 +72,7 @@ describe("telling somebody what an LDIF re-import duplicated", () => {
   it("counts an entry that matches an existing card on name and address", async () => {
     server([card("c1", "Jane Doe", "[email protected]")]);
     const r = await useContacts.getState().importLdif(entry("Jane Doe", "[email protected]"), "book1");
-    expect(r).toEqual({ created: 1, skipped: 0, alike: 1 });
+    expect(r).toEqual({ created: 1, updated: 0, alike: 1 });
   });
 
   it("imports it anyway, which is the whole point of counting rather than matching", async () => {
@@ -124,7 +124,7 @@ describe("telling somebody what an LDIF re-import duplicated", () => {
   it("counts nothing against an empty book", async () => {
     server([]);
     const r = await useContacts.getState().importLdif(entry("Jane Doe", "[email protected]"), "book1");
-    expect(r).toEqual({ created: 1, skipped: 0, alike: 0 });
+    expect(r).toEqual({ created: 1, updated: 0, alike: 0 });
   });
 
   it("does not count the file against itself", async () => {
@@ -133,6 +133,6 @@ describe("telling somebody what an LDIF re-import duplicated", () => {
     server([]);
     const twice = entry("Jane Doe", "[email protected]") + "\n" + entry("Jane Doe", "[email protected]");
     const r = await useContacts.getState().importLdif(twice, "book1");
-    expect(r).toEqual({ created: 2, skipped: 0, alike: 0 });
+    expect(r).toEqual({ created: 2, updated: 0, alike: 0 });
   });
 });