CSW filters don't match Dublin Core identifiers

[rcoup]

Dublin core records aren't retrievable via CSW GetRecords queries using a filter on the dc:identifier element.

1. add a record (via template, upload, or CSW Transaction). See example attachment.
2. head to ​http://localhost:8080/geonetwork/srv/en/test.csw and paste in the following query. Notice how you get 0 results.

   <csw:GetRecords xmlns:csw="http://www.opengis.net/cat/csw/2.0.2" 
    xmlns:gmd="http://www.isotc211.org/2005/gmd" service="CSW"
    version="2.0.2" resultType="results">
       <csw:Query typeNames="csw:Record">
           <csw:Constraint version="1.1.0">
               <Filter xmlns="http://www.opengis.net/ogc">
                   <PropertyIsEqualTo>
                       <PropertyName>dc:identifier</PropertyName>
                       <Literal>12345678-1234-1234-abcd-12345678901a</Literal>
                   </PropertyIsEqualTo>
               </Filter>
           </csw:Constraint>
       </csw:Query>
   </csw:GetRecords>
   

3. Change the query to the following. Notice how you get 1 result, so the record is definitely there.

   <csw:GetRecords xmlns:csw="http://www.opengis.net/cat/csw/2.0.2" 
    xmlns:gmd="http://www.isotc211.org/2005/gmd" service="CSW"
    version="2.0.2" resultType="results">
       <csw:Query typeNames="csw:Record">
           <csw:Constraint version="1.1.0">
               <Filter xmlns="http://www.opengis.net/ogc">
                   <PropertyIsLike wildCard="*" escape="\" singleChar="?">
                       <PropertyName>dc:title</PropertyName>
                       <Literal>*Test*</Literal>
                   </PropertyIsLike>
               </Filter>
           </csw:Constraint>
       </csw:Query>
   </csw:GetRecords>
   

• Using identifier, apiso:identifier, dc:identifier, Id, etc as the PropertyName doesn't make any difference.
• ISO19139 records are returned (using a PropertyName of either apiso:identifier, dc:identifier, or identifier), it appears to be only Dublin Core records that are affected.
• the dc:identifier is in the metadata DB table as the uuid for the record.
• using other filters (eg. PropertyIsLike) on the dc:identifier element doesn't work either.

[rfw]

Change the mapping of Identifier from fileId to _uuid (see following comment)

[rfw]

This appears to be due to the Identifier field being mapped to fileID, a field that is only present in ISO19139 records and not Dublin Core -- in Dublin Core, the field is stored as identifier in the database.

However, the _uuid field is available for both Dublin Core and ISO19139 and contains the correct value for both formats. I'm not sure if it is intended to work that way, but I have attached a patch regardless for config-csw.xml to change the mapping.