feat: add webhooks for major events for DLE 4.0 (#514)

Description

Add webhooks for major events

• Extend DLE config to support webhooks (clone_create, clone_reset, clone_delete, snapshot_create (via API only!), snapshot_delete (via API only!), branch_create, branch_delete)
• Support webhook configuration reloading
• Make requests and report status and response to logs
• Filter webhook secrets in logs

Related issue

#514

The previous MR: !760 (closed)

Examples

Configuration

webhooks:
  hooks:
    - url: "http://127.0.0.1:2345/healthz"
      secret: "secret-token"
      trigger:
          - clone_create
          - clone_reset

Checklist

• MR description has been reviewed
• MR changes are functionally tested
• MR does NOT have API/CLI changes OR there are API/CLI changes and they have been reviewed & DOCS ARE ADJUSTED (reference doc, etc)
• MR does NOT have UI changes OR there are UI changes and they have been reviewed & UX IS REVIEWED

Closes #514