TriggerMenuMT: Introduce typesafe ChainProp class

Frank Winklmeierrequested to merge
fwinkl/athena:tmmt_chainprop into master

Change the ChainProp class from namedtuple to dataclass with some limited type-checking code (could be replaced once we have an external type-checker available in LCG).

Also fix bug in the chain group assignment of a few chains discovered by this additional check.

Merge request reports