chore(postgresql): rename app folder and add icon

packages/backend/src/apps/postgresql/common/postgres-client.ts

@@ -0,0 +1,20 @@
+import knex, { Knex } from 'knex';
+import { IGlobalVariable } from '@automatisch/types';
+
+const getClient = ($: IGlobalVariable): Knex<any, unknown[]> => {
+  const pgClient = knex({
+    client: 'pg',
+    version: $.auth.data.version as string,
+    connection: {
+      host: $.auth.data.host as string,
+      port: Number($.auth.data.port),
+      user: $.auth.data.user as string,
+      password: $.auth.data.password as string,
+      database: $.auth.data.database as string,
+    }
+  })
+
+  return pgClient;
+};
+
+export default getClient;