feat(rest-api): expose backup-log in the SSE

[MathieuRA]

Description

tested on all kind of backups.

• snapshot
• delta-backup
• full-backup
• continuous replication
• disaster recovery
• pool metadata
• mirror full backup
• mirror incremental backup
• sequence that run backups

[mathieura@vates-mathieu ~]$ curl http://local-xoa:9000/rest/v0/events -u admin:admin
event: init
data: {"id":"825fbf8f-9868-4515-92c3-5b7acea6211c"}
// in another terminal: curl http://local-xoa:9000/rest/v0/events/825fbf8f-9868-4515-92c3-5b7acea6211c/subscriptions --json '{"collection": "backup-log", "fields":["status", "data"]}' # (you can use "fields": "*" if you prefere to watch any change)
// then run my backup

event: add
data: {"$subscription":"backup-log","status":"pending","data":{"mode":"delta","reportWhen":"failure"}}

event: update
data: {"$subscription":"backup-log","status":"success","data":{"mode":"delta","reportWhen":"failure"}}

Checklist

• Commit
  • Title follows commit conventions
  • Reference the relevant issue, forum thread, discussion, ... (Fixes #007, See xoa-support#42, See https://...)
  • If bug fix, add Introduced by <commit|PR>
• Changelog
  • If visible by XOA users, add changelog entry to CHANGELOG.unreleased.md
  • If visible by XO Lite users, add changelog entry to @xen-orchestra/lite/CHANGELOG.md
  • Update "Packages to release" in CHANGELOG.unreleased.md
• PR
  • If UI changes, add a ### Screenshots section above this checklist
  • If not finished or not tested, open as Draft

Review process

• External contributors: simply open the pull request, we'll get back to you as soon as possible.
• Vates developers: follow the internal pull request process.