feat: adds flutter unit tests and report

[kukkok3]

Description

This PR adds a earthly target to run unit and widget tests plus test report

Related Issue(s)

List the issue numbers related to this pull request.

Closes #328

Description of Changes

• Renamed integration_test.dart into integration_tests.dart so it is not picked up by flutter test command
• Added a earthly target to run flutter unit tests tests and produce test reports
• Added test report to github workflow to be picked up by allure

Breaking Changes

Describe any breaking changes and the impact.

Screenshots

If applicable, add screenshots to help explain your changes.

Related Pull Requests

If applicable, list any related pull requests.

e.g., #1, #1

Please confirm the following checks

• My code follows the style guidelines of this project
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream module

[github-actions]

✅ Test Report | ${\color{lightgreen}Pass: 25/25}$ | ${\color{red}Fail: 0/25}$ |