Adjust notes positions/sizes after post replacement

[RaisingK]

Notes aren't being automatically adjusted after post replacements. Didn't they used to do that?

[evazion]

Example post? It works on my devbooru, and the testcase for this in the test suite passes too.

[RaisingK]

EB brought this up after replacing post #3218976 and post #3218975. All of the posts I've replaced so far in pool #14211 (post #3224182, post #3224185, ...) have had this issue.

[evazion]

It turns out this happens only when the "Final Source" field is set during the replacement. It worked when the final source wasn't set.