Base64 encode PM titles and bodies in the database.

To prevent personal discomfort with having to do database messages and seeing people's personal conversations.
I haven't run into it yet, but I'd rather avoid it altogether.

database/2024_06_02_194809_base_sixty_four_encode_pms_in_db.php

@@ -0,0 +1,14 @@
+<?php
+use Index\Data\IDbConnection;
+use Index\Data\Migration\IDbMigration;
+
+final class BaseSixtyFourEncodePmsInDb_20240602_194809 implements IDbMigration {
+    public function migrate(IDbConnection $conn): void {
+        $conn->execute('UPDATE msz_messages SET msg_title = TO_BASE64(msg_title), msg_body = TO_BASE64(msg_body)');
+        $conn->execute('
+            ALTER TABLE `msz_messages`
+                CHANGE COLUMN `msg_title` `msg_title` TINYBLOB NOT NULL AFTER `msg_reply_to`,
+                CHANGE COLUMN `msg_body`  `msg_body`  BLOB     NOT NULL AFTER `msg_title`;
+        ');
+    }
+}