feat: support deny action in bindings

[f1ames]

This PR adds support for Deny action in policy bindings. It partially solves #10. It is based on and targets f1ames/feat/cloud-integration branch and should be merged after it.

Now, for Warn action, the list of violations is send as warnings. For Deny it is same but send as regular output, additionally resource is blocked and so it is interpreted as error by client (e.g. kubectl).

As stated in VAP docs (which we try to align) with:

Deny and Warn may not be used together since this combination needlessly duplicates the validation failure both in the API response body and the HTTP warning headers.

Changes

• As above.

Fixes

• None.

Checklist

• tested locally
• added new dependencies
• updated the docs
• added a test

[murarustefaan]

lgtm!