fix: add postgres backend

changes:
- Add postgres backend
- Modified or added table attributes.
  UpdateDate, ForeignKeys, Booleans
- Fix test for sqlite and postgres. Compare json instead the struct.

Makefile

@@ -159,6 +159,7 @@ container-run:
 	${CONTAINER_RUNTIME} run \
 		--rm \
 		--volume ${PWD}:/workspace \
+		--volume /var/run/docker.sock:/var/run/docker.sock \
 		docker.io/volkerraschek/build-image:latest \
 			make ${COMMAND} \
 				GOPROXY=${GOPROXY} \