Added FrameDifferenc(FilterEquals) node that filter equal frames

[dani217s]

PR Details

Adds a FrameDifference node that can filter out equal frames

Description

When the speed of the Mainloop is faster than the speed of the frame grabber, it happens that FrameDifference is executed on the same frame and the output of FrameDifference is a black image. The proposed node can avoid this behavior

Related Issue

Motivation and Context

Types of changes

• [ ] Docs change / refactoring / dependency upgrade
• [ ] Bug fix (non-breaking change which fixes an issue)
• [x] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)

Checklist

• [ ] My change requires a change to the documentation