Network policy editor model

What does this MR do?

This commit implements a basic foundation for the NetworkPolicy model that will be used in the new policy editor. This model was added to the relevant fields of the editor. Additionally yaml preview was implemented to display policy changes in real time. This is a part of the ongoing works towards &3403 (closed).

related to #223660 (closed) and #223647 (closed)

Screenshots

initial state	with changes

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers
• Informed Infrastructure department of a default or new setting change, if applicable per definition of done

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• Label as security and @ mention @gitlab-com/gl-security/appsec
• The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• Security reports checked/validated by a reviewer from the AppSec team