fix: Close viewer if we navigate back in browser history

[juliusknorr]

Browser history handling is kind of odd with viewer, this is an attempt to have a small fix for #486 while this should be properly addressed with #2395

We could also do this by using the vue-router in files, but since there is no exposed method to register navigation guards, using native browser APIs seems more straight forward as a backportable fix.

Also this will only fix going backward but if a user decides to go forward in history again, the openfile parameter is not triggering the viewer again. Probably something to check in the files app separately.

I'm not sure if there is a better way to implement this. Would appreciate any feedback

[skjnldsv]

Could you add cypress tests? :)

[juliusknorr]

Sure, added a simple one

[juliusknorr]

/compile amend

[juliusknorr]

/backport to stable30

[juliusknorr]

/backport to stable29

[backportbot]

The backport to stable29 failed. Please do this backport manually.

# Switch to the target branch and update it
git checkout stable29
git pull origin stable29

# Create the new backport branch
git checkout -b backport/2661/stable29

# Cherry pick the change from the commit sha1 of the change against the default branch
# This might cause conflicts, resolve them
git cherry-pick 18477e4b

# Push the cherry pick commit to the remote repository and open a pull request
git push origin backport/2661/stable29

Error: No changes found in backport branch

---

Learn more about backports at https://docs.nextcloud.com/server/stable/go.php?to=developer-backports.