Move Trigger and TDC config to testbench.yaml

Having now more configuration parameters for our readout system (TLU/Trigger, TDC) I think it would be a good idea to move Trigger/TLU and TCD configuration at one place (to testbench.yaml) instead of having it at several places (source scan, ext trigger scan, ...). The settings specified in the yaml would then be loaded if the module is needed/activated.

For TDC I think it would be nice to introduce a parameter use_tdc which can be set in order to use TDC (with settings specified in testbnech.yaml).

What do you think?