perf: improve global performance when using many genericobject

[stonebuzz]

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.
• This change requires a documentation update.

Description

• It fixes !35986

improve global performance when using many genericobject

When a GLPI page is loaded (depending of context) a itemtype created by genericobject can be registered at least 9 times (see on ticket page)

With 200 object -> 1800 registerType call ..

So before registerType (which done many action) check if already register in $_SESSION

Before

After

Screenshots (if appropriate):