[Improvement]: Add "Force Resize" Flag to Video Thumbnails

[solverat]

Improvement description

Issue

Currently, it is not possible to skip video resizing when the uploaded video is already smaller than the configured target width or height.

This can lead to undesirable upscaling of videos. For example, when a user uploads a vertical video and a “Scale by Width” transformer is active, the system will upscale the video to match the configured width. This often results in reduced visual quality and/or huge filesizes.

Solution

Adding a "Force Resize" checkbox like in Image thumbnails.

This checkbox should be enabled by default to maintain backward compatibility (BC) and preserve the current behavior.