[ATR-19441] Add KeyWriterTool, instantiate Online and Offline instances
Add tool which writes the trigger key triplet.
Instantiate this in the Online world and the Offline world.
[ATR-19441] will use these data to sanity-check that we are reading the SAME configuration offline as we ran online.
L1PrescaleSet now available, but not online. Added a new parameter to the key-writer tool to let it ignore the L1PS for when it is running online.