Run events every given number of seconds (#2512)
* WIP
* Fix implementation
* Fix units
* Rename
* Delete dead code
* This works
* Fix tests
* Final fix - still rough
* Reduce code duplication
* Fixing bugs + test
* Changelog
* Add gif to changelog
* Update demo and remove unused imports
* undo accidental diff
* Linting
* Add to guides
* Address comments
* formatting changelog
* Fix warnings
