RC7: Minor: Shortcut for Favourites

[Dreamer]

Ctrl+F1 and temporary also Alt+F1.

Same action as if I click on fav. button.

Reasons/Advantages:

- we can't use fav. with keyboard, it would be possible with Ctrl+F1 shortcut
- we don't have "Drive button", but with this option we could add drives C:, D: ... to fav. and use it as in file managers (shortcut Alt+F1)

I think it would be very good and (maybe) easy to implement solution.

[xnview]

Ctrl+F1 and temporary also Alt+F1.

Same action as if I click on fav. button.

Reasons/Advantages:

- we can't use fav. with keyboard, it would be possible with Ctrl+F1 shortcut
- we don't have "Drive button", but with this option we could add drives C:, D: ... to fav. and use it as in file managers (shortcut Alt+F1)

I think it would be very good and (maybe) easy to implement solution.

Please not in 1.80