test: Fix unstable test with wrong assertions

[viacheslavkol]

Purpose

Fix unstable test with wrong assertions.
Test body suggests that item should be updated but assertion verifies that there was only 1 create event and it's unstable because there's no wait so sometimes it wrongly passes when update event is not captured for the time of the assertion.
x-okapi-url headers are inconsistent across integration tests, sometimes vertx url is used, sometimes - wiremock url.

Approach

Rework assertion to wait for the update event.
Use wiremock url when appllicable for http client, kafka assertion, use vertx url otherwise

Changes Checklist

• API Changes: Document any API paths, methods, request or response bodies changed, added, or removed.
• Database Schema Changes: Indicate any database schema changes and their impact. Confirm that migration scripts were created.
• Interface Version Changes: Indicate any changes to interface versions.
• Interface Dependencies: Document added or removed dependencies.
• Permissions: Document any changes to permissions.
• Logging: Confirm that logging is appropriately handled.
• Unit Testing: Confirm that changed classes were covered by unit tests.
• Integration Testing: Confirm that changed logic was covered by integration tests.
• Manual Testing: Confirm that changes were tested on local or dev environment.
• NEWS: Confirm that the NEWS file is updated with relevant information about the changes made in this pull request.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

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