[FR] Add a keyboard shortcut to switch between media fields

Proposal Summary

We can currently use the left and right arrows to go to the previous and next sample. It would be very useful if we could also go to the previous and next media field of a sample (e.g. by using page up and page down).

Motivation

This feature would make switching between media field faster, since we currently have to click a couple boutons (which is pretty slow).

What areas of FiftyOne does this feature affect?

• App: FiftyOne application
• Core: Core fiftyone Python library
• Server: FiftyOne server

Willingness to contribute

• Yes. I can contribute this feature independently
• Yes. I would be willing to contribute this feature with guidance from the FiftyOne community
• No. I cannot contribute this feature at this time