Add AttachmentsCopier concern

[aapomm]

Spec

When moving an instance of evidence to another node the attachments are not moved. This means that if we delete the original node, the attachments are destroyed and the attachment can no longer be referenced in the evidence.

Proposed solution
Copy the attachment to the new node when an evidence or note are moved

• In the controller's update action, check if the node_id is being changed
• If yes, check whether the text includes any attachment syntax (!/projects/1/nodes/1/attachments/img.jpeg!)
• If yes, find the attachment by file name and node_id and copy the attachment to the new node
• Update the evidence/note text with the reference to the new node's attachment.

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Check List

• Added a CHANGELOG entry

[etdsoft]

good consistency move.

[etdsoft]

I'm concerned about this text manipulation. Then I thought about the "copy link" feature of the attachments sidebar, perhaps we can use the same approach?

https://github.com/dradis/dradis-ce/blob/main/app/views/attachments/_attachment_box.html.erb#L59

I could even consider moving this into a helper to avoid duplication, but we don't currently have an attachment_helper.rb it could fit in.

[aapomm]

It's tricky to DRY this considering that the contexts are different. The attachment box is in the view that has access to the route helpers while this code isn't. There's also some possible rabbit hole with the default_url_options = /pro once we move the link helpers out of the view. Happy to explore this more if we need this code on many more places but currently, this seems like the simplest approach.