Add enabled Flag to Transitions

[reinecke]

trafficstars

New Feature

Description

In #1175 the enabled flag was added to the Item schema. This would also be useful to add to transitions as well.

#1187 addresses adding this flag for Effects.

[jspada200]

Would this be a good first issue for Dev Days?

[meshula]

Since this landed for Effects we should prioritize this for implementation, otherwise we've got a straggling outlier.