* prevent working timeout and grace period from being set to negative numbers
* add extra validation
* lint
* fix black
* fix isort
* add js tests
* fix lint + more python schema validation
* add report schema test for timeout limits
* add extra test for null grace period
* add rc4 changelog entries
(cherry picked from commit 5719fefdd4)
* only show grace period for alerts + fix dropdown styling
* fix lint
Co-authored-by: Ville Brofeldt <ville.v.brofeldt@gmail.com>