Add initial carddav support

crates/store/migrations/2_addressbook.sql

@@ -0,0 +1,34 @@
+CREATE TABLE addressbooks (
+    principal TEXT NOT NULL,
+    id TEXT NOT NULL,
+    synctoken INTEGER DEFAULT 0 NOT NULL,
+    displayname TEXT,
+    description TEXT,
+    deleted_at DATETIME,
+    PRIMARY KEY (principal, id)
+);
+
+CREATE TABLE addressobjects (
+    principal TEXT NOT NULL,
+    addressbook_id TEXT NOT NULL,
+    id TEXT NOT NULL,
+    vcf TEXT NOT NULL,
+    updated_at DATETIME DEFAULT CURRENT_TIMESTAMP,
+    deleted_at DATETIME,
+    PRIMARY KEY (principal, addressbook_id, id),
+    FOREIGN KEY (principal, addressbook_id)
+    REFERENCES addressbooks (principal, id) ON DELETE CASCADE
+);
+
+CREATE TABLE addressobjectchangelog (
+    -- The actual sync token is the SQLite field 'ROWID'
+    principal TEXT NOT NULL,
+    addressbook_id TEXT NOT NULL,
+    object_id TEXT NOT NULL,
+    operation INTEGER NOT NULL,
+    synctoken INTEGER DEFAULT 0 NOT NULL,
+    created_at DATETIME DEFAULT CURRENT_TIMESTAMP,
+    PRIMARY KEY (principal, addressbook_id, created_at),
+    FOREIGN KEY (principal, addressbook_id)
+    REFERENCES addressbooks (principal, id) ON DELETE CASCADE
+);