Creating new package for JSON monitoring

Following the discussing in PR#5013, the JSON monitoring code has been moved to its own package (HLTrigger/JSONMonitoring). Aside from the necessary changes in include commands, the build file and the seal module, this code is identical to PR#5013. The description copied from the latter is below.

This is the initial version of the trigger monitoring via JSON files. For now, all it does is print a pair of JSON files per process to the mon subdirectory of the base directory provided by the EvFDaqDirector service. The first file (the definition) has the names of all HLT paths and the second has the counts in each lumi section.