WIP Update cms-eventdisplay-files.xml

Addressing issues: https://github.com/cernopendata/opendata.cern.ch/issues/311  https://github.com/cernopendata/opendata.cern.ch/issues/154 https://github.com/cernopendata/opendata.cern.ch/issues/333 and https://github.com/cernopendata/opendata.cern.ch/issues/223
> It replaces 774 as explained in #223

That's OK, but the newly introduced link text should use "Foo bar baz" spelling, not "Foo Bar Baz" spelling, as discussed in #357.