fix: put all compose files in the same namespace

This avoids the error about container name conflicts, and also gives a warning about orphaned `ghostfolio` image running (if you don't use `--remove-orphans`), which is probably what we want?

docker/docker-compose.build.yml

@@ -1,4 +1,4 @@
-name: ghostfolio_build
+name: ghostfolio
 services:
   ghostfolio:
     build: ../

docker/docker-compose.dev.yml

@@ -1,4 +1,4 @@
-name: ghostfolio_dev
+name: ghostfolio
 services:
   postgres:
     extends: