Implement PNG alpha channel removal in OCR processing

[R0Wi]

• PNG preprocessing via Imagick
• Refactor code to use base class for OCR processors

[sonarqubecloud[bot]]

Quality Gate failed

Failed conditions
60.7% Coverage on New Code (required ≥ 80%)

See analysis details on SonarQube Cloud

[sonarqubecloud[bot]]

Quality Gate passed

Issues
1 New issue
0 Accepted issues

Measures
0 Security Hotspots
94.4% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[R0Wi]

The backport to stable32 failed:

The process '/usr/bin/git' failed with exit code 1

To backport manually, run these commands in your terminal:

# Fetch latest updates from GitHub
git fetch
# Create a new working tree
git worktree add .worktrees/backport-stable32 stable32
# Navigate to the new working tree
cd .worktrees/backport-stable32
# Create a new branch
git switch --create backport-310-to-stable32
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick ---mainline 1 34dd7cfd20b020b381b5269da9ac0234055cc0c5
# Push it to GitHub
git push --set-upstream origin backport-310-to-stable32
# Go back to the original working tree
cd ../..
# Delete the working tree
git worktree remove .worktrees/backport-stable32

Then, create a pull request where the base branch is stable32 and the compare/head branch is backport-310-to-stable32.