Speed up multiple clips at once [request]

SUMMARY

It's not possible to adjust the speed of multiple clips at once.

STEPS TO REPRODUCE

1. Add multiple clips to timeline
2. Select the clips
3. Right click on the last one and select "Change Speed"
4. Adjust the speed and confirm
5. The change was applied to one track only

OBSERVED BEHAVIOR

The user can select multiple clips in the timeline and apply a speed-up from the context menu. But this affects only the last clip (the one that was clicked).

EXPECTED BEHAVIOR

All selected clips are sped up. It does not matter where the right click was applied as long as all clips were selected.

ENV DETAILS

kdenlive-20.12.3a-x86_64.appimage
OS: KDE neon User Edition 5.21 x86_64
Kernel: 5.4.0-70-generic
KDE Plasma Desktop: 5.21.3