files Rewrite overwrite prompt for link case

Follow-up for #1989. Split into a separate PR so the functionality of the main one could be merged.

I think this is a more understandable wording for this case. I am open to feedback on this though.

Note that it fails to compile, seemingly because the result of printf is owned, but primary and secondary are unowned. I'm not quite sure how to fix this.

I also added a doc comment for create_overwrite_dialog while here.

Jun 10 '22 22:06 mcclurgm

@mcclurgm I have tried to fix this consistent with @Marukesu 's suggestions (although I have reworked the string handling a little differently). It now compiles and seems to work with the builtin portal tester and also the Flatpak version of Code. I have little experience of documenting functions - I have tried to follow the format in existing projects but there may be some tweaking required.

Jul 27 '22 10:07 jeremypw

@Marukesu Could cast another eye over this? Particularly the method documentation I added. The CI failure is not related to this PR - it seems to be happening to all PRs merged with the current master but I haven't determined the reason yet (it doesn't happen locally so something to do with the container?)

Feb 19 '23 18:02 jeremypw