📍 Support cognizance / oversight reassignment

[danswick]

Follows #4402.

As part of uniform guidance (ref, we need to be able to reassign cognizance or oversight for a given report. According to guidance, any agency can ask for a reassignment provided that both the original and destination agencies agree with the reassignment. Some rough requirements here (we'll need to refine later):

• Develop a process for getting sign-off from both agency parties
• Develop some method for capturing the relevant sign-off information at time of reassignment (probably similar to how we're handling validation waivers now)
• Create a workflow for doing the actual reassignment on the relevant audit report record
• Figure out how to disseminate the new assignment info