CLOUDP-361352 - fix get_all_rs and related methods in multi_cluster_reconcile_races E2E Test

[filipcirtog]

Summary

Resource Management and Configuration Updates:

• Updated the get_mdbmc helper to set the MongoDB version, configure the resource with the correct cluster spec, and update the associated ConfigMap to use the new external OM base URL, ensuring that MongoDBMulti resources in member clusters use the external address for OM.
• Adjusted the get_sharded helper to explicitly set the custom MongoDB version.

Test Logic and Assertion Improvements:

• Added cross cluster support so OM is actually reachable, before we were not actually accessing om and thus weren't able to download the agent
• Refined test cases to assert the running phase of all relevant resource types (replica sets, multi-cluster, sharded, and standalone) instead of using one that didn't work

Proof of Work

passing https://spruce.mongodb.com/task/mongodb_kubernetes_e2e_operator_race_ubi_with_telemetry_e2e_om_reconcile_race_with_telemetry_patch_c6c02208534df8bed84316b5062db92c8f4e1087_69306528ba7d830007e2495c_25_12_03_16_28_27/logs?execution=0

Checklist

• Have you linked a jira ticket and/or is the ticket in the title?
• Have you checked whether your jira ticket required DOCSP changes?
• Have you added changelog file?
  • use skip-changelog label if not needed
  • refer to Changelog files and Release Notes section in CONTRIBUTING.md for more details

[github-actions]

⚠️ (this preview might not be accurate if the PR is not rebased on current master branch)

MCK 1.6.1 Release Notes

Bug Fixes

• Backed up the agent password in a secret for SCRAM authentication to prevent unnecessary password rotations.

[lucian-tosa]

This test has Istio enabled, it shouldn't require this.

[nammn]

Why not - do I missunderstand something? This test requires the multi cluster components to be able to access OM, which the latest commit adds to fix this test.