Add Postgres migration for special folders

SQL/postgres.initial.sql

@@ -34,6 +34,14 @@ CREATE TABLE ident_switch
     smtp_port
 		integer
 		CHECK(smtp_port > 0 AND smtp_port <= 65535),
+    drafts_mbox
+        varchar(64),
+    sent_mbox
+        varchar(64),
+    junk_mbox
+        varchar(64),
+    trash_mbox
+        varchar(64),
 	UNIQUE (user_id, label)
 );
 

SQL/postgres/2019121300.sql

@@ -0,0 +1,14 @@
+ALTER TABLE
+  ident_switch
+ADD COLUMN
+	drafts_mbox
+    varchar(64),
+ADD COLUMN
+	sent_mbox
+    varchar(64),
+ADD COLUMN
+	junk_mbox
+    varchar(64),
+ADD COLUMN
+	trash_mbox
+    varchar(64);