API for scheduled backups.

[Arnav15]

Set markActive to true to enable multi-table backup. Change it to false in case the universe needs to be updated in the middle of a multi-table backup task for graceful termination of the backup task.

curl -X PUT \
  'http://localhost:9000/api/v1/customers/f33e3c9b-75ab-4c30-80ad-cba85646ea39/universes/a1691c27-e999-4647-a303-125b028b64bf/update_backup_state?markActive=true' \
  -H 'Content-Type: application/json' \
  -H 'Postman-Token: 6e6657dd-3bc6-4e21-b99e-e21c1ec4d62a' \
  -H 'X-AUTH-TOKEN: 7e7630b8-6ce9-433a-b3aa-931eb5979b0e' \
  -H 'cache-control: no-cache'

This is the actual call to trigger the schedule/backup. It can take the following params:
storageConfigUUID: Required. Same as the value for an individual backup in that universe.
schedulingFrequency: Time in millisecs between each schedule.
cronExpression: A unix style cron-expression to signify the recurrence of the schedule.
Both of the above aren't required, but if one is provided, the other one should be null. If none of them is provided, it is considered a one-off task and is not run on a schedule.
sse: True or False (defaults to False). Not required

curl -X PUT \
  http://localhost:9000/api/v1/customers/f33e3c9b-75ab-4c30-80ad-cba85646ea39/universes/a1691c27-e999-4647-a303-125b028b64bf/multi_table_backup \
  -H 'Content-Type: application/json' \
  -H 'Postman-Token: 615143e7-daa6-4f92-afc6-2f7bbc659a62' \
  -H 'X-AUTH-TOKEN: 7e7630b8-6ce9-433a-b3aa-931eb5979b0e' \
  -H 'cache-control: no-cache' \
  -d '{"storageConfigUUID": "2ee3e0ff-881e-41e6-b841-496b7b7afb63", "cronExpression": "*/5 * * * *"}'