fix: Use new viewer api to open files again after open locally

[juliusknorr]

Steps to reproduce:

• Open a file in Collabora
• Click the open locally button
• Confirm to open locally
• Click continue editing online

Before:

• Nothing happened

After:

• Properly reopens Collabora

[juliusknorr]

/backport to stable28

[juliusknorr]

/backport to stable27

[juliusknorr]

Cypress needs a separate fix, also fails on master

[backportbot]

The backport to stable28 failed. Please do this backport manually.

# Switch to the target branch and update it
git checkout stable28
git pull origin stable28

# Create the new backport branch
git checkout -b backport/3524/stable28

# Cherry pick the change from the commit sha1 of the change against the default branch
# This might cause conflicts, resolve them
git cherry-pick d646f67c

# Push the cherry pick commit to the remote repository and open a pull request
git push origin backport/3524/stable28

Error: Failed to create pull request: Validation Failed: {"resource":"PullRequest","code":"custom","message":"A pull request already exists for nextcloud:backport/3524/stable28."}

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