fix(files_external): broken credentials dialog

[skjnldsv]

The browsers behavior changed and some stopped prompting the native browser auth dialog on xhr requests.

This replaces it with a proper dialog.
Fix #44497

[susnux]

Looks good!

[skjnldsv]

/compile rebase /

[skjnldsv]

/backport to stable30

[skjnldsv]

/backport to stable29

[skjnldsv]

/backport to stable28

[skjnldsv]

/backport 0f519f4 to stable30

[skjnldsv]

/backport 0f519f4 to stable29

[skjnldsv]

/backport 0f519f4 to stable28

[backportbot]

The backport to stable30 failed. Please do this backport manually.

# Switch to the target branch and update it
git checkout stable30
git pull origin stable30

# Create the new backport branch
git checkout -b backport/47945/stable30

# Cherry pick the change from the commit sha1 of the change against the default branch
# This might cause conflicts, resolve them
git cherry-pick 0f519f4

# Push the cherry pick commit to the remote repository and open a pull request
git push origin backport/47945/stable30

Error: Failed to create pull request: Validation Failed: {"resource":"PullRequest","code":"custom","message":"A pull request already exists for nextcloud:backport/47945/stable30."}

---

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

[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/47945/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 0f519f4

# Push the cherry pick commit to the remote repository and open a pull request
git push origin backport/47945/stable29

Error: Failed to create pull request: Validation Failed: {"resource":"PullRequest","code":"custom","message":"A pull request already exists for nextcloud:backport/47945/stable29."}

---

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

[backportbot]

The backport to stable30 failed. Please do this backport manually.

# Switch to the target branch and update it
git checkout stable30
git pull origin stable30

# Create the new backport branch
git checkout -b backport/47945/stable30

# Cherry pick the change from the commit sha1 of the change against the default branch
# This might cause conflicts, resolve them
git cherry-pick 0f519f4

# Push the cherry pick commit to the remote repository and open a pull request
git push origin backport/47945/stable30

Error: Failed to create pull request: Validation Failed: {"resource":"PullRequest","code":"custom","message":"A pull request already exists for nextcloud:backport/47945/stable30."}

---

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

[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/47945/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 0f519f4

# Push the cherry pick commit to the remote repository and open a pull request
git push origin backport/47945/stable28

Error: Failed to create pull request: Validation Failed: {"resource":"PullRequest","code":"custom","message":"A pull request already exists for nextcloud:backport/47945/stable28."}

---

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