Add support for archiving items (#6916)

* Add archiving

* Update Diesel macros and remove unnecessary SUPPORTED_FEATURE_FLAG

* Add IF EXISTS to down.sql migratinos

* Rename migration folders, separate logic based on PR threads

migrations/postgresql/2026-03-09-005927_add_archives/down.sql

@@ -0,0 +1 @@
+DROP TABLE IF EXISTS archives;

migrations/postgresql/2026-03-09-005927_add_archives/up.sql

@@ -0,0 +1,8 @@
+DROP TABLE IF EXISTS archives;
+
+CREATE TABLE archives (
+    user_uuid   CHAR(36) NOT NULL REFERENCES users (uuid) ON DELETE CASCADE,
+    cipher_uuid CHAR(36) NOT NULL REFERENCES ciphers (uuid) ON DELETE CASCADE,
+    archived_at TIMESTAMP NOT NULL DEFAULT now(),
+    PRIMARY KEY (user_uuid, cipher_uuid)
+);