[Feature]: Implement helper functions and data classes in preparation for ERS and other handlers

[emmuhamm]

Description

To implement the new and improved ERS functionality and other related streams, daqpytools needs a few things implemented:

• HandlerConf data class to store the relevant handler configurations
• Definition of the filters that are attached to each of the handlers to allow us to choose when an already existing handler should fire or not, based on the handler configuration that was passed to it
• The ability to parse the handler configurations of ERS from OKS, as it is defined there. See: https://github.com/DUNE-DAQ/daqsystemtest/blob/974965be6e96aff969c69a380ed34aa96705e802/config/daqsystemtest/ccm.data.xml#L189

Potential impact radius

Small/Isolated

Reason for change

No response

Suggested implementations

No response

Testing suggestions

No response

Anything else?

No response