Further devcontainer updates

- Bump postgresql image from 13 to 15
- Store psql data in the dev/psql directory
- Install required frontend packages

.devcontainer/docker-compose.yml

@@ -1,11 +1,11 @@
 services:
   db:
-    image: postgres:13
+    image: postgres:15
     restart: unless-stopped
     expose:
       - 5432/tcp
     volumes:
-      - inventreedatabase:/var/lib/postgresql/data:z
+      - ../dev/psql/:/var/lib/postgresql/data:z
     environment:
       POSTGRES_DB: inventree
       POSTGRES_USER: inventree_user
@@ -40,6 +40,3 @@ services:
 
     depends_on:
       - db
-
-volumes:
-  inventreedatabase: