added validation of primary/unique keys, plus added warnings in forward-engineering script when primary/unique constraints have no keys

Author: pdesmarets

package.json

@@ -1,7 +1,7 @@
 {
     "name": "PostgreSQL",
-    "version": "0.1.20",
-    "versionDate": "2022-06-03",
+    "version": "0.1.21",
+    "versionDate": "2022-06-17",
     "author": "hackolade",
     "engines": {
         "hackolade": "6.1.2",