Resolve "videoOpenCV SFrameWriter uses the wrong timestamp in file names"

What does this MR do?

Use the timeline timestamp instead of the current timestamp when saving frames using videoOpenCV::SFrameWriter

How to test it?

• Launch and test frameMatrixRecorder to save frames
• Check that the timestamps look good!

Data

No needed data

Additional tests to run

• Build on Windows
• Build on Linux
• Build on MacOS

Closes #44 (closed)