Support "Pending" for program_data.status

[jdalphond-mitre]

This is actually already supported, but for data integrity, we should enforce an enum on this field

"active"
"inactive"
"pending"

Target is v2.8.5

Add tests to validate success and failure cases.

[jdalphond-mitre]

@Ewgna After looking at the data in production. Use Uppercase "Pending" "Inactive" and "Active" and update the checks for updating timestamps.