Nightly test to detect changes of classes in Trigger EDM

Summary of updates:

• Updates StreamerInfoGenerator needed due to changes in Python binding introduced in ROOT 6.22
• Make dictwrite.py callable from other packages, to use in a nightly test
• Add the test itself. The test reads list of classes that are stored in Trigger EDM and detects whether in a given nightly build the checksum of TStreamerInfo class object is changed compared to what is already stored in bs-streamerinfos.root. If it is, the test is failed and will ask the Trigger EDM coordinator to update the streamerinfos file. This should help preventing errors in bytestream decoding in newer releases with evolved classes.