Fix a bunch of warnings/errors (#479)

* Remove invalid ref={} prop

* Fix <rect> height being less than 0

* Improve history.push override

* Filters: add missing key prop

* DateSelect: don’t pass `null` to an input

* Filters: add missing key prop

* EditRule: fix key props

* ScheduleDetails: Fix `for` prop

* usePayees: default `payees` to empty array instead of null (fixes crash)

* safeNumber: better error if `value` is not a number

* ScheduleDescription: fix description for “amount is between”

* ScheduleDetails: add missing `key` prop

* BudgetTitlebar: use ButtonWithLoading