Change iid argument to ID_TYPE for graphQL queries

What does this MR do?

It changes all iid arguments in graphQL queries to ID_TYPE. We use ID_TYPE for id arguments and iid is basically the same. But for iid in some places, we use STRING_TYPE. This MR unifies the iid argument type across all graphQL endpoints.

Does this MR meet the acceptance criteria?

Conformity

• [-] Changelog entry
• [-] Documentation (if required)
• Code review guidelines
• [-] Merge request performance guidelines
• [-] Style guides
• [-] Database guides
• Separation of EE specific content

Closes #208394 (closed)