Fix: check host id before forwarding to Centreon API

[Rom1-B]

Checklist before requesting a review

Please delete options that are not relevant.

• I have performed a self-review of my code.
• I have added tests (when available) that prove my fix is effective or that my feature works.
• I have updated the CHANGELOG with a short functional description of the fix or new feature.
• This change requires a documentation update.

Description

• It fixes #N/A
• The Centreon host actions (check, downtime, acknowledgement, timeline) now validate that the
  requested host id actually maps to a GLPI item the current user can access before contacting
  the Centreon API.
• The HTTP client used to reach the Centreon API now uses default certificate verification
  instead of an explicit override.
• The composer.json dependency declaration for the HTTP client library was corrected to match
  the convention used by other plugins that rely on the copy bundled with GLPI core.

Screenshots (if appropriate):