Water Use Equipment Drop zones don't let you overwrite schedules

[DavidGoldwasser]

Closely related to Issue #532 The drop zone doesn't let you overwrite the schedule that is there. If you have a schedule on any of the dropzones and try to drag an alternate one there you get the circle/slash icon.

you have to first delete the schedule that is there and then drag a new one. This again seems to be unique to the water use equipment def object.

cc: @elainethale

[kbenne]

@DavidGoldwasser is this still a thing?

[DavidGoldwasser]

@kbenne both this and issue #532 are both still valid. Just tested in develop. I'm going to change it to minor. While you can't just drop a new schedule on top of an existing one. If you hit the "x" to clear out a schedule then you can add a new one. Elsewhere in the GUI this isn't required.

Checking type limit enforcement elsewhere in the GUI. In some drop zones it is enforced, in others it isn't.

[jmarrec]

Addressed by GUI refactor