Remove self_monitor_form.vue component and related files

Relevant files

• app/assets/javascripts/self_monitor/components/self_monitor_form.vue
• app/assets/javascripts/self_monitor/index.js
• spec/frontend/self_monitor/components/self_monitor_form_spec.js
• app/assets/javascripts/self_monitor/store/*
• spec/frontend/self_monitor/components/__snapshots__/self_monitor_form_spec.js.snap
• spec/frontend/self_monitor/store/*
• app/views/admin/application_settings/metrics_and_profiling.html.haml

Any other files that have usages of the component.