Update security configuration tabs to utilize lazy loading

Context

Currently the tabs on the "Security & Compliance" configuration page does not utilize lazy loading, which means not-needed data could be loaded.

Solution

Using the lazy prop on <gl-tabs> within app/assets/javascripts/security_configuration/components/app.vue makes sure we only use the data we need.

Note: The newly added "Vulnerability Management" tab (behind the feature flag :secure_vulnerability_training) already has a loading state, but we might need to add this to the other two tabs.

Implementation Plan

• Update tab in app/assets/javascripts/security_configuration/components/app.vue to use lazy prop
• Make sure we have loading states and add if not for all tabs