Intuitive button icons for importing and exporting joystick and functions mappings

[ES-Alexander]

• Clicking these should open a dialogue that allows choosing whether to import/export from/to the vehicle's onboard computer or the device running the Cockpit frontend (relevant to #556)
• Base functionality and interim/alternative UI in #630

[amleshwar-p]

I would like to work on this.

[ES-Alexander]

Hi @amleshwar-p - thanks for your interest! :-)

You're welcome to submit a pull request to resolve this if you'd like to. There are some visual suggestions in the parent issue.

Let us know if there's anything you're not clear on.