Merge begin and end dates for location actions

As a user I don't want to handle the location actions for configurations (static or dynamic) splitted in begin actions and end actions.

Acceptance criteria:

• rename contact to begin_contact, description to begin_description for static location begin actions
• rename contact to begin_contact, description to begin_description for dynamic location begin actions
• end_date, end_contact & end_description is in the static location action model
• end_date, end_contact & end_description is in the dynamic location action model
• database migration for both the static location actions as well as the dynamic location actions
• rename endpoints (no longer begin or end naming)
• rename types in the schemas (no longer begin or end)
• remove the database entries for end actions in a database migration
• adjust handling in the elasticsearch payload (send both begin_description and end_description)
• Adjust tests accordingly