Bug when editing records with file uploads

[bergmania]

When loading a form record using ?recordId=xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx,
A YSOD appears due to the file upload.

[azure-devops-sync]

This item has been added to our backlog AB#1043

[warrenbuckley]

V7 PR for this is here
https://github.com/umbraco/Forms/pull/289

[warrenbuckley]

V8 fix was done as part of this PR - https://github.com/umbraco/Forms/pull/288

[warrenbuckley]

V7 PR merged in now too - https://github.com/umbraco/Forms/pull/289