[E2E] Add tests for enabling traits at IntegrationPlatform

[tadayosi]

As a follow-up to #3205, there's no test coverage that verifies Integration runs when traits are enabled at IntegrationPlatform like this:

apiVersion: camel.apache.org/v1
kind: IntegrationPlatform
metadata:
  labels:
    app: camel-k
  name: camel-k
spec:
  traits:
    addons:
      tracing:
        enabled: true
    jolokia:
      enabled: true

Unlike when enabled at Integration, these tests can make sure the traits don't crash during kit building as when they are enabled at IntegrationPlatform they are also forced to be enabled during kit building while an integration is still absent.