fix: append coreAnalyzer if active_filter is empty and integration is added

[matthisholleville]

Closes #412

📑 Description

✅ Checks

• My pull request adheres to the code style of this project
• My code requires changes to the documentation
• I have updated the documentation as required
• All the tests have passed

ℹ Additional Information

(matthisholleville) ➜  k8sgpt git:(fix/integration-and-filters) go run main.go filters list                
Active: 
> PersistentVolumeClaim
> Ingress
> Node
> Deployment
> ReplicaSet
> StatefulSet
> CronJob
> Pod
> Service
Unused: 
> HorizontalPodAutoScaler
> PodDisruptionBudget
> NetworkPolicy
(matthisholleville) ➜  k8sgpt git:(fix/integration-and-filters) go run main.go integration activate trivy
...
Activated integration trivy
(matthisholleville) ➜  k8sgpt git:(fix/integration-and-filters) go run main.go filters list              
Active: 
> Deployment
> Ingress
> Node
> Service
> CronJob
> ReplicaSet
> PersistentVolumeClaim
> VulnerabilityReport (integration)
> Pod
> StatefulSet
Unused: 
> HorizontalPodAutoScaler
> PodDisruptionBudget
> NetworkPolicy

[panpan0000]

👍