feat: Replace mongo package with monc & mon (#2002)

* Replace mongo package with monc & mon

* Add terminal whitespace

* format code

tools/goctl/test/main.sh

@@ -0,0 +1,6 @@
+#!/bin/bash
+
+# main.sh is the entry point for the goctl tests.
+
+# testing mongo code generation.
+/bin/bash integration/model/mongo/mongo.sh