Umbrella Add Tetrate Enterprise Capability

Forward the capability from Operator Istio allowing the use of non-Iron Bank Istio images / Tetrate Images and any other additional Tetrate configuration in Operatorless Istio.

See: https://repo1.dso.mil/big-bang/product/packages/istio-controlplane/-/blob/main/chart/values.yaml?ref_type=heads#L12