Resolve "Change the exposure-lib to use the `AbstractDatabase` class for database polymorphism"
In this MR the ExposureDatabase class will be expanded into SpatiaLiteExposure and PostGISExposure classes that are derived from a common AbstractExposure and the respective database classes from the database-lib. These changes are the basis for the exposure-distributor to run on both database types with the same code base.
Closes #40 (closed)
Edited by Danijel Schorlemmer