Asynchronous Execution of Indicators in a Batch

[PascalHonegger]

As a user of the data quality framework, I would like to have the possibility to execute indicators in parallel / asynchronously in a given indicator group. This should allow a faster execution of a batch.

Example of solution design:

• Indicators currently have an attribute "execution order". It it used to order the execution of indicators in an indicator group.
• All indicators having the same value for execution order could be executed in parallel during a batch.