Add FlexMeasures plugins, USEF protocol, and Cariflex simulator

- flexmeasures-entsoe: ENTSO-E data plugin
- flexmeasures-weather: Weather data plugin
- USEF Flex Trading Protocol PDF (2.4MB)
- Cariflex simulator (publishes to Redis)
- Dashboard Grafana updated with correct InfluxDB queries
- All tools extracted in /tools/

tools/flexmeasures-weather/requirements/dev.in

@@ -0,0 +1,11 @@
+-c app.txt
+-c test.txt
+
+pre-commit
+black
+flake8
+flake8-blind-except
+mypy
+pytest-runner
+setuptools_scm
+watchdog