feat: Add a variable that enables/disables network policies

[omohammed95]

Description of the changes

This PR introduces a variable to enable or disable network policies for Thanos components. Previously, the network policy values were hard-coded, limiting flexibility and customization. By adding this variable, users can easily configure network policies as per their requirements.

Breaking change

• No

Tests executed on which distribution(s)

• AKS (Azure)

[lentidas]

I do not think that this will be this simple... back from when I tested this, simply enabling the network policies broke the communication between the other modules and the Thanos module. Also, since we deploy a Redis for caching metrics, we will also need to create and deploy customized Network Policies to regulate that network traffic.

And one more thing, I think naming the variable network_policy_thanos is not the best name, since this variable will also exist on other modules. In my opinion, something like enable_network_policies would be more adequate.