[scripts] Removed older scripts

scripts/event_header_generator/EventStrings.cpp.template

scripts/event_header_generator/Events.h.template

scripts/event_header_generator/README.md

scripts/event_header_generator/Topics.h.template

scripts/event_header_generator/credentials.json

scripts/event_header_generator/event_generator.py

scripts/event_header_generator/requirements.txt