MetaData - Put the plugin names into the meta data of the database

Moin moin everybody,

this MR streaamlines the metadata. Instead of writing

P0 <shared lib0>
P1 <shared lib1>
P2 <shared lib2>

as individual columns to the databse, I propose to write

PluginLibs <shared lib0>;<shared lib1>;<shared lib2>

further, I realized that we can exploit the getName() method of the GeoVPlugins themselves to also publish the system names. So I added

BuiltDetectors <detName 0>;<detName 1>;<detName 2>;

The advnatage, we can use this column of the AAAHEADER table to deduce super easily in athena which subdetectors are in the file nad toggle the Detector flags accordingly. We may need to fiddle the plugin names in GeoModelATLAS

@boudreau, @tsulaia what do you think?