Add "NAS" Option on whisky age

[Sleni82]

A lot of whiskies doesnt have an age statement for different reasons. Whiskies should be able to have a "NAS" tag instead of a number (see attached screenshot).

For fun and if we like it, someone trying to add a number lower than 3 should get a massage saying "Thats not a whisky, enter 3 years or more " Could be for future.
This because it is not allowed to call spirit a whisky unless its more than 3 years :)