Add the capability to prevent features with feature filters from being evaluated.

[jimmyca15]

This PR adds an enhancement to define features with feature filters that should not be evaluated.

There are times when developers configure feature filters for a feature but they do not want this feature to be on. This could be pre-emptive configuration of a feature to include feature filters that is later turned on. Or it could be that a feature is frequently turned off/on but there is a desire to preserve the configuration of filters.

Here is an example feature that has a feature filter registered, but should not be evaluated.

{
  "FeatureManagement": {
    "NonEvaluatedFeature": {
      "Evaluate": false,
      "EnabledFor": [
        {
          "Name": "MyFeatureFilter"
        }
      ]
    }
  }
}

For this feature, await IsEnabledAsync("NonEvaluatedFeature") will return false.