After #9542, the format for `functions -Dv` was changed for copied
functions.
```diff
-stdin
-n/a
+[path to copy location]
+[path to original definition]
[and a few more lines]
```
Some components were (and perhaps are) still expecting the old format,
however. After a search, it looks like `funced` and `fish_config` are
the only two functions using `functions -D` and `functions -Dv` in this
repo (none are using `type -p`).
As noted in issue #11614, `funced` currently edits the file which
copies the given copied function. Another option was to make `funced`
edit the file which originally defined the function. Since the copied
function would not have been updated either way, I modified `funced` so
it would pretend that the copied function was defined interactively,
like it was before.
I did not modify `fish_config`, since it was only used for preset
prompts in the web config, none of which used `functions --copy`.
(Moreover, I believe it would have behaved correctly, since the preset
would not have had to define the function, only copy it.)
Fixes issue #11614
