feat: implement application cloning

Application cloning can be used to setup review applications based on an existing application. This is useful in CI/CD pipelines where a developer may wish to verify code in a custom environment without overwriting a shared staging environment.

plugins/apps/commands

@@ -8,6 +8,7 @@ case "$1" in
       declare desc="return apps plugin help content"
       cat<<help_content
     apps, List your apps
+    apps:clone <old-app> <new-app>, Clone an app
     apps:create <app>, Create a new app
     apps:destroy <app>, Permanently destroy an app
     apps:rename <old-app> <new-app>, Rename an app