Add endpoints for rating endpoint (dislikes)

https://github.com/ajayyy/SponsorBlock/issues/1039

databases/_upgrade_private_4.sql

@@ -0,0 +1,14 @@
+BEGIN TRANSACTION;
+
+CREATE TABLE IF NOT EXISTS "ratings" (
+	"videoID"		TEXT NOT NULL,
+	"service"		TEXT NOT NULL default 'YouTube',
+	"type"			INTEGER NOT NULL,
+	"userID"		TEXT NOT NULL,
+    "timeSubmitted"	INTEGER NOT NULL,
+	"hashedIP"		TEXT NOT NULL
+);
+
+UPDATE "config" SET value = 4 WHERE key = 'version';
+
+COMMIT;