FEAT: Change Catagories to a list

cms/internal/db/migrations/0002_normalize_video_categories.down.sql

@@ -0,0 +1,3 @@
+DROP TABLE video_categories;
+
+ALTER TABLE videos ADD COLUMN category_id SMALLINT REFERENCES categories(id);

cms/internal/db/migrations/0002_normalize_video_categories.up.sql

@@ -0,0 +1,7 @@
+ALTER TABLE videos DROP COLUMN category_id;
+
+CREATE TABLE video_categories (
+    video_id     UUID NOT NULL REFERENCES videos(id) ON DELETE CASCADE,
+    category_id  SMALLINT NOT NULL REFERENCES categories(id),
+    PRIMARY KEY (video_id, category_id)
+);