[tests-only] test: Cleanup OTP Credentials after MFA

[kavitagautam]

Description

This PR adds cleanup of existing OTP/TOTP credentials for the Keycloak admin user before and after E2E tests.

• Added beforeEach cleanup to remove existing OTP/TOTP credentials before each Keycloak test.
• Added afterEach cleanup to remove OTP/TOTP credentials created during the test.
• Set the Keycloak access token before performing the cleanup.
• Updated deleteUserTotpCredentials() to resolve the Keycloak user UUID by username instead of relying on keycloakCreatedUser.

Related Issue

• [QA] Add e2e tests for Vault mode web#13864

Motivation and Context

How Has This Been Tested?

• test environment:
• test case 1:
• test case 2:
• ...

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Technical debt
• Tests only (no source changes)

Checklist:

• Code changes
• Unit tests added
• Acceptance tests added
• Documentation ticket raised:

[update-docs]

Thanks for opening this pull request! The maintainers of this repository would appreciate it if you would create a changelog item based on your changes.

[kw-security]

✅ Snyk checks have passed. No issues have been found so far.

Status	Scan Engine	Critical	High	Medium	Low	Total (0)
✅	Open Source Security	0	0	0	0	0 issues
✅	Licenses	0	0	0	0	0 issues
✅	Code Security	0	0	0	0	0 issues

💻 Catch issues earlier using the plugins for VS Code, JetBrains IDEs, Visual Studio, and Eclipse.

[PrajwolAmatya]

LGTM, lets wait for Trivy scan to be fixed. 👍