Fix m->d then d->m reactions not merging

src/db/migrations/0023-add-original-encoding-to-reaction.sql

@@ -0,0 +1,5 @@
+BEGIN TRANSACTION;
+
+ALTER TABLE reaction ADD COLUMN original_encoding TEXT;
+
+COMMIT;

src/db/orm-defs.d.ts

@@ -110,6 +110,7 @@ export type Models = {
 		hashed_event_id: number
 		message_id: string
 		encoded_emoji: string
+		original_encoding: string | null
 	}
 
 	auto_emoji: {