Add primary keys to multiple tables

I missed these keys when creating the initial schema, and it's a useful practice.

config/sql/se/TocEntries.sql

@@ -1,5 +1,7 @@
 CREATE TABLE `TocEntries` (
+  `TocEntryId` int(10) unsigned NOT NULL AUTO_INCREMENT,
   `EbookId` int(10) unsigned NOT NULL,
   `TocEntry` text NOT NULL,
+  PRIMARY KEY (`TocEntryId`),
   KEY `index1` (`EbookId`)
 ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;