Hub user access silently drops mismatched query values

### Feature Summary

The hub user-access endpoint combines `entityType` and `entityId` query values with `zip` without validating that the lists have equal lengths. An extra ID or type is silently ignored, so the response does not represent the full request.

Before: mismatched query lists return 200 after dropping the unmatched value.

Expected: mismatched query lists return 400, while equal-length lists keep working.

Reproduction evidence:

1. Launch Texera from current `main`.
2. Request `GET /api/hub/user-access?entityType=workflow&entityId=7&entityId=8`.
3. Observe a 200 response containing only entity 7.
4. Reverse the mismatch by sending two types and one ID and observe the extra type is also ignored.

Version and commit evidence:

1.3.0-incubating-SNAPSHOT (main)

**Commit Hash (Optional)**

98588bf2ab49aac65ebf002496eb057670e6fc07

**What browsers are you seeing the problem on?**

Not browser-specific.

**Relevant log output**

No server error is logged because the unmatched query value is silently discarded.

### Proposed Solution or Design

Expected: mismatched query lists return 400, while equal-length lists keep working.

### Affected Area

Workflow Engine (Amber)