Feature request: Option to customize destroy previous attachment

[khoan]

Currently, there are no options to customize how previous attachment is destroyed except for monkey patching, see more https://github.com/markevans/dragonfly/issues/365.

Possible use case is soft delete policy where a marker is used to indicate destruction but actual data is not destroyed.

[bsvin33t]

I'm interested in this feature, but a slight variation of this(replace instead of delete and re-upload). I don't mind building this. But I need help in theory crafting how to allow this configuration to be allowed. cc: @khoan 😃