Provide bank data for financial applications as a SQLite DB and add support for data update

The idea is to integrate the support for query and generation of SQLite databases into KtoBLZCheck to replace the text files used currently. This will avoid duplicate data and enable the support for multiple countries improving the scope of this library. An API would be made available to allow integration of this database into other financial applications. An API would also be added to download updates for the data file.