Auto completion / for stored field, return values from records that user could see

[fxp]

Autocompletion is looking the index for terms corresponding to the field requested but does not take into account user privileges. Results may contain terms which come from records that user can not see.

In some cases, we could enhance this by first running a search and looking for field values from the topDocs of the search. This will work if the field is stored (which is not always the case - eg. any). If no values found, we fallback on previous method.

[fxp]

Commit ​https://github.com/geonetwork/core-geonetwork/commit/5e66647bf6e83f1cc9a5d6909669d4091b187778