Customizable skip video shortcuts

[marktaipan-cvisionai]

Category Feature request

Problem Currently limited to 1 frame, 1 second, and 1 minute skips using keyboard shortcuts in the video annotator.

Request Could either:

1. Add additional keyboard shortcuts. Have to consider available shortcuts.
2. Allow the user to select what the jump should be. Perhaps in the video settings dialog this can be set and stored locally in cache that would be project specific.

Also as part of this, it would be worth changing the keyboard icon to a text CTRL label. The icon has caused confusion.