fix: SonarQube report - refs #305404

[avoinea]

Problem

After Jenkins pipeline update, test libraries changed behavior. Previously, skipped tests still generated empty XML report files. Now, no XML files are generated when tests are skipped. SonarQube scan fails because coverage/junit-results/testreports/*.xml glob matches nothing.

Root Cause

Packages had only test_doctests.py using legacy Plone testing (plone.testing.z2, PloneSandboxLayer, FUNCTIONAL_TESTING layer). These doctests loaded README.txt files with no actual doctest content (>>> lines) → always skipped → no test report generated.

Fix

• Removed dead test_doctests.py and base.py (legacy Plone 4/5 testing infrastructure)
• Added real unit tests using unittest.TestCase that actually run and generate test reports
• Tests use pure functions / light mocking, no Plone integration layer needed

Refs #305404