[STORAGE] added _parse_statements method

The method is internally used by queryFromFile and will return a list of SQL statements given an open file pointer with a SQL file
[TESTS] added tests for _parse_statements method
[STORAGE] removed exception catching in queryFromFile so it propagates back
[STORAGE] do not implicitly call DatabaseStorage.connect() in DatabaseStorage __init__
[STORAGE] on database connection (mysql) attempt to create the necessary tables if B3 database is empty
[TESTS] adapted storage tests and added new test cases for B3 database table generation