Add testRigor end-to-end tests

[luccarojasc]

Add testRigor End-to-End Tests and CI Integration

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This PR introduces a new set of end-to-end (E2E) tests powered by testRigor.

Example of a run with the tests included on this pull request:
https://app.testrigor.com/test-suites/4jN3KbixMSQa6cdYn/runs/zEfSgxo7Q9ch6mN6w

Requirements for this PR to be merged:

Include the environment variable/secret SUITE_ID and CI_TOKEN into the upstream repository.
This can be done by:

Set up a new Open Source account for OpenHRMS

1. Enter https://testrigor.com/sign-up/ Select the radio-button "Public Open Source" and create an account;
2. Validate your e-mail;
3. Create a new test suite;
4. Copy the Test Suite ID https://app.testrigor.com/test-suites/XXXXXXXXXXXX where "XXXXXXXXXXX" represents your Suite's ID;
5. Add the OPENHRMS_SUITE_ID presented on the test suite URL as a repository variable in GitHub;
6. Copy the OPENHRMS_TOKEN from the field auth-token on the CI/CD Integration tab ( /ci or click the "CI/CD Integration" button );
7. Add the OPENHRMS_TOKEN as a repository secret in GitHub.

OR
I can share the token for the current suite used to test this pull request with OrangeHRM manteiners.

Why testRigor?

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Open Source projects thrive when contributors can easily verify changes and ensure nothing breaks. testRigor offers advantages that are particularly valuable for a community-driven project like OpenHRMS:

• Natural language test cases: Anyone can contribute automated tests without any language-specific coding skills, broadening the contributor base and allowing a higher test coverage;
• Reduced maintenance overhead: Tests are resilient to UI changes, lowering the cost of keeping the suite up to date;
• Cross-platform coverage: Support across different environments and setups such as mobile, desktop and web;
• Faster feedback loop: Catch issues earlier in PRs and maintain higher project stability.