fix: zero test result

[kinsolee]

Changes

• fix: zero test result
  Allow IsEmpty returns false even if there is no test cases included in a test execution(failed, passed, skipped are all 0), provided that PassedTestsRate is not empty string.

Scenario: Expect below task result could be injected into buildRun.status rather than omitted.

testResults:
  failed: 0
  passed: 0
  passedTestsRate: "0.00"
  skipped: 0

apiVersion: builds.katanomi.dev/v1alpha1
kind: BuildRun
metadata:
  name: katanomi-adefs
  namespace: default
status:
  unitTestsResults:
    - name: existing-result
      coverage:
        lines: "11"
        branches: "11.33"
    - name: unittest // this item will be omitted if IsEmpty returns true in this scenario.
      testResults:
        passed: 0
        skipped: 0
        failed: 0
        passedTestsRate: "0.00"

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