Remove network policy constants

What does this MR do and why?

Remove network policy constants

• remove unused constants
• update tests
• remove unused mock data
• remove reliance on environment store. I will remove the store in another MR
• rename constants in the NetworkPolicies namespace to SecurityOrchestration, which is more general. I have verified that these constants are not translated, so we will not be losing anything by changing the namespace

Related to #352285 (closed)

What does this MR NOT do and why?

There have been many MRs related to #352285 (closed) to remove the network policy editor. Remove network policy editor (!85855 - merged) was the latest that removed most of the code. This MR cleans up some constants and environment dependencies. The environment store will be deleted in a later MR (and is documented in the issue). This MR does NOT touch any of the backend files (like the helpers that pass up the environment data) because that would be too much for this MR; that change is coming.

Screenshots or screen recordings

Before	After
	No visual change

How to set up and validate locally

1. Upload a GitLab Ultimate license
2. Navigate to a project => Security & Compliance => Policies => New policy
3. Verify all editors still work

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.