Tyk Gateway Chart is missing Topology Spread Constraint

[JanMa]

Hello,

I would like to ensure our Tyk Gateway deployment in Kubernetes is high
available and can handle certain common failure scenarios like loss of an
availability zone. The standard way to do this, is to set a Topology Spread Constraint
in the Kubernetes deployment. This ensures all Pods are spread evenly across all
existing availability zones. 

The Tyk Gateway HELM chart does not support setting this, please add it as a
configuration option..