Update CMS primary data sets

Addressing issues: https://github.com/cernopendata/opendata.cern.ch/issues/89 https://github.com/cernopendata/opendata.cern.ch/issues/333 https://github.com/cernopendata/opendata.cern.ch/issues/154 https://github.com/cernopendata/opendata.cern.ch/pull/91#discussion_r17281750
https://github.com/cernopendata/opendata.cern.ch/issues/223
Shall we keep leading `$a Data` note?  E.g. some records may have `Software` or other text inside perhaps; see [alice-analysis-modules.xml](https://github.com/cernopendata/opendata.cern.ch/blob/pu/invenio_opendata/testsuite/data/alice/alice-analysis-modules.xml):

```xml
    <datafield tag="256" ind1=" " ind2=" ">
      <subfield code="a">Software (1 file, 31139203 bytes)</subfield>
    </datafield>
```