metadatavalues with admin security level are indexed in solr

[floriangantner]

Describe the bug
MetadataValues with some restrictive security level are indexed in the search.

To Reproduce
Steps to reproduce the behavior:

1. Define some configuration for some metadatafield with multiple configurable security levels, e.g. 0 public and 2 admin
2. Generate some metadatavalue for this metadatafield and save the item
3. search for this metadatavalue using the discovery

Expected behavior
We would expect hidden metadatavalues not to be indexed and being searchable.

We would expect the Indexer to exclude metadatafields based on global configuration and metadatafield-specific configuration settings.

Related work