Fixing issues with the WebUI and the optical cybersecurity module

This MR focuses on fixing the issues reported in two issues:

• Closes #57 (closed)
• Closes #102 (closed)

The changes are as follows:

• Version of the Flask package has been updated to fix the issues in the WebUI.
• The tests of the opticalattackdetector have been reworked to fix the issue.

The pipelines are here:

• Optical attack detector: https://labs.etsi.org/rep/tfs/controller/-/jobs/51936
• WebUI: https://labs.etsi.org/rep/tfs/controller/-/pipelines/4220

src/opticalattackdetector/service/OpticalAttackDetectorServiceServicerImpl.py

@@ -221,7 +221,7 @@ class OpticalAttackDetectorServiceServicerImpl(OpticalAttackDetectorServiceServi
             monitoring_client.IncludeKpi(kpi)
 
         # if -1 in response.cluster_indices:  # attack detected
-        if kpi.kpi_value.int32Val == -1:
+        if kpi.kpi_value.int32Val == 1:
             attack = AttackDescription()
             attack.cs_id.uuid = request.service_id.service_uuid.uuid
             with HISTOGRAM_DURATION.labels(step="mitigation", **METRIC_LABELS).time():