Storage of available databases and meta information

[JetamZ]

The aim is to create another "common database" which would contain the information on what corpora are available within the application,
along with some meta information about databases containing information from available corpora.
This database can then be queried by the web server to provide user useful tips on what information is there to use

• List of available databases
• List of columns within such databases (what information do we keep)

(so far)