TrigOutputHandling: Migrate to IOptionsSvc

Migrate HLTResultMTMaker and TriggerEDMSerialiserTool to the new IOptionsSvc interface. No change in functionality. The parsing works slightly different now and in some cases we can just rely on the default value of IOptionsSvc::get for non-existent properties (e.g. when running offline).

Also apply similar changes to the legacy RandomScaler (this code is really not used anymore and will eventually be deleted) and delete some unused IJOptionsSvc.h includes in trigger monitoring packages.

cc @rbielski @wiedenma