Use IstioGw + AppGw in terraform instead of AGIC

• Use istiogw instead of agic controller and test in glab, this might decrease downtime which seems to be happening. (Issue with the AGIC controller)

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Current work done so far it was to enable by default istio AppGw in the terraform code, however, as we are moving towards deprecate AGIC, we need to implement different module or create logic in module to modify the routing rules accordingly, as current terraform code, ignore http backend rules and so on, also we need to agreed on some static ip address to be used by default for istio gw and this internal ip address should be used as well in the helm-charts-azure.

It will require to handle correctly the letsencrypt/acme certificate issuer, which currently it is not working correctly and job in helm-charts-azure keeps failing constantly, we should attempt to fix the job as well as to make this certification smoother using maybe istio-ingress-class.

Main issue it would be that AppGw should expose port 80 as well, therefore some rule might need be needed to handle the default 80 port or redirect to proper https service, means this change should be applied on infra and helm