feat(policy-devel): support providing allowed hostnames

[migmartri]

running a policy that calls to an invalid endpoint

$ chainloop policy develop eval --kind EVIDENCE --material ~/work/chainloop/playground/policies/test-http/empty.json -p ~/work/chainloop/playground/policies/test-http/test-http.yaml
ERR evaluating policy: failed to execute policy : failed to evaluate policy: test-http:36: eval_builtin_error: http.send: unallowed host: app.chainloop.dev

providing the hostname it works

chainloop policy develop eval --kind EVIDENCE --material ~/work/chainloop/playground/policies/test-http/empty.json -p ~/work/chainloop/playground/policies/test-http/test-http.yaml --allowed-hostnames app.chainloop.dev
[
   {
      "violations": [
         "Platform version violation: expected '1.2.3', got 'v0.256.0'"
      ],
      "skip_reasons": [],
      "skipped": false
   }
]