As a Developer I want to be able to query with context for KPI Analytics

Problem

1. It is currently not possible to run queries with a specified context, like for example the current group. Only platform-wide statistics are supported. By adding the possibility for a context in the query a range of possibilities would open.
2. The module itself hasn't been touched much since it was first created, so it's a good idea to refactor parts of it so it becomes more stable and adheres to the latest coding standards.

Solution

1. Module should be able to parse the context in the data source, e.g. run query for the current group.
2. Refactor parts of the module so it complies better with