Add AI input limits

[julien-nc]

Add a 64K char limit for text input in:

• TranslationApiController::translate()
• TextToImageController::schedule()
• TextProcessingApiController::schedule()
• TaskProcessingApiController::schedule()

[julien-nc]

/backport to stable32

[julien-nc]

/backport to stable31

[julien-nc]

/backport to stable30

[julien-nc]

/backport to stable29

[julien-nc]

/backport to stable28

[julien-nc]

/backport to stable27

[backportbot]

The backport to stable27 failed. Please do this backport manually.

# Switch to the target branch and update it
git checkout stable27
git pull origin stable27
# Create the new backport branch
git checkout -b backport/56350/stable27
# Cherry pick the change from the commit sha1 of the change against the default branch# This might cause conflicts, resolve them
git cherry-pick 33d1acdd
# Push the cherry pick commit to the remote repository and open a pull request
git push origin backport/56350/stable27

Error: Failed to check for changes with origin/stable27: No changes found in backport branch

---

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/56350/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 33d1acdd
# Push the cherry pick commit to the remote repository and open a pull request
git push origin backport/56350/stable28

Error: Failed to check for changes with origin/stable28: No changes found in backport branch

---

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/56350/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 33d1acdd
# Push the cherry pick commit to the remote repository and open a pull request
git push origin backport/56350/stable29

Error: Failed to check for changes with origin/stable29: No changes found in backport branch

---

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