Reduce code duplication Alert / Incident Management

Summary

From this comment: !37889 (comment 387208500)

Currently we have a set of duplication between ~"Category:Alert Management" and Category:Incident Management code, we should reduce this by abstracting where we can.

Involved components

• app/assets/javascripts/incidents/components/incidents_list.vue
• app/assets/javascripts/alert_management/components/alert_management_table.vue