All indexes have now the same names, cta-catalogue-schema-verify now checks for user created indexes

Added a class SchemaChecker that has the responsiblity of checking :
- the schema against the .sql defined in the SCHEMA_VERSION/xxx_catalogue_schema.sql
- the presence of PARALLEL tables in ORACLE (not implemented yet)

A directory is created regarding the version of the catalogue, the xxx_catalogue_schema.sql is inserted in it at each modification of the schema by the user

 directive is silently ignored by eos fst, but it still has to be a valid executable file. Just to clearly state that this does not need to be changed to /opt/eos/... CTA uses eos-xrootd packages.